Since 2.0.2 there's a frustrating bug the iPhone doesn't remember the WiFi password. But there is a fix for jailbroken iPhones: Connect via ssh to your iphone and enter the following command:

• chmod 777 -R /private/var/Keychanins/

On the iPhone select Settings -> General -> Reset -> Reset Network Settings

The iPhone will reboot itself and the problem is fixed.

I found it very inefficient to mod your local keyboard files in order to disable auto-correction, because you lose the ability to enable auto-correction quickly. A better way is to mod a language file which you'll never use, like Swedish, which doesn't even have a dictionary. I've modded the Swedish plist file, to match the English strings. How to use it:

1. Copy this plist file to /System/Library/Frameworks/UIKit.framework
2. Remove the Swedish dictionary (TextInput_sv.bundle) in /System/Library/Textinput
3. Enable the Swedish keyboard in Settings -> General -> Keyboard -> International Keyboards
4. Enable the keyboard for example in a text message, click on the globe icon on the left side untill you see 'None', which actually stands for: No Dictionary
5. Done! Enjoy faster text input, without losing your local keyboard dictionary.

So you're running iPhone firmware 2.0.1, having the Cydia package manager installed and you're running SSH. You are also aware of the fact Cydia is slowing down your phone with it's "Base Structure" updates and you want to get rid of it but keeping SSH and still having the possibility to re-install Cydia again ? Here you go:

• Make sure MobileTerminal is installed, you can find it in the "System" section of Cydia
• Open Terminal and enter the following commands:
• 
  
  su root
< enter password >
apt-get remove cydia
Yes, do as I say!
killall Springboard
  
  
• Done!

To re-install Cydia, enter install in stead of remove

To skip the backup proces of iPhones running 2.0 (or higher ?) but leaving a backup option in the iPhone contextual menu to manually backup your device, enter the following commands in your terminal after you quit iTunes:

• 
  

• defaults write com.apple.iTunes AutomaticDeviceBackupsDisabled -bool true
• defaults write com.apple.iTunes DeviceBackupsDisabled -bool true
• 
  To re-enable backups:
  
  
• defaults write com.apple.iTunes DeviceBackupsDisabled -bool false
• 
  Keep in mind your applications, text messages and your email and calendar stuff aren't backed up anymore,
  but if you use MobileME, and you keep a local copy of your text messages (/var/private/mobile/library/SMS/sms.db), your quiet safe..
  
  

To enable support for cracked IPA files, follow these steps:

1. Using sFTP (SSH File Transfer Protocol) (i.e. Cyberduck), navigate to the folder: /System/Library/PrivateFrameworks/MobileInstallation.framework
2. Backup the file: "MobileInstallation" in this directory
3. Copy this patched MobileInstallation file over to this directory, make sure the file has no extension
4. Set permissions to that new file to 775
5. Reboot your iPhone (IMPORTANT! Otherwise Apps will not install!)
6. Restart iTunes
7. Double click on IPA files so they will appear in iTunes and synchronize
8. Done

Sometimes your iPhone freezes and looses information. As example the SMS database. I've had some freezes in the SMS application which resulted in an empty SMS database.

Luckely enough, iTunes makes an backup of your iPhone, everytime it syncs. This backup contains preferences, notes, SMS messages, call history and photo's.

When you're in a situation where the iPhone lost, for example, the SMS database, DON'T sync, but just remove the following folder:

/var/mobile/Media/iTunes_Control/iTunes/
 

Now connect your iPhone again with your mac, iTunes will detect the iPhone as a new device, and asks you if you want to restore a previous backup.


Click "Continue", your iPhone will be restored to the previous databases and settings, while keeping your applications etc.

On 1.1.3 or 1.1.4 (or maybe higher), the "passwd" utility refused to work correctly and could mess up your springboard. The tool is necessary to change the password on BSD Subsystem 2.1. To fix this problem, replace the existing "passwd" binary file with the given.

Download and extract passwd.zip,
and move the file with AFPd (for example) to /usr/bin/ , chmod to 755:
# cd /usr/bin
# chmod 755 passwd
# passwd
# Enter new password:
# ...


Only for Dutch iPhone users.

Voor KPN gebruikers, dit is een KPN Carrier bundle.
Deze bundles bevatten informatie over een operator netwerk en er kan ook een operator logo worden mee gegeven.

Deze bundle bevat standaard informatie over het KPN-netwerk (voicmail nummer e.d.) maar ook een KPN logo.

Voer de volgende stappen uit om de bundle door de iPhone toe te kennen aan de KPN MMC/MNC-codes:

1. Download KPN.bundle
2. Plaats de file in /System/Library/Carrier Bundles/ via SFTP of AFP
3. Maak een symbolic hard-link aan:
   
   • cd /System/Library/Carrier Bundles/
   • ln -s KPN.bundle 20408
   • Reboot
4. Klaar

Yes it's possible ! You can have 1.1.4 on your iPhone while keeping the 4.6 bootloader. The advantage of keeping 4.6 is the possibility to flash a custom bootloader in the future, which isn't possible with the 3.9 bootloader. It's also not possible to upgrade from 3.9 to 4.6, so if you got BL 4.6, this guide is for you!

Here we go:

1. Restore your iPhone to 1.1.4 with iTunes.
   You can find 1.1.4 here
2. Download ZiPhone 2.2 and 2.5c
3. Keep your iPhone with iTunes connected and run ZiPhone 2.5c
4. Click on Advanced, and check Jailbreak Activation, and start the proces
5. When the proces is finished, quit ZiPhone 2.5c and start ZiPhone 2.3b
6. Check 'Unlock' and start the proces
7. Done !

Now you have a full working iPhone, with firmware version 1.1.4, bootloader 4.6, modem (baseband) version 04.02.13_G and working "Locate Me" feature !

After installing Geohot's software unlock for 1.1.2/3 OTB, my iPhone was REALLY messed up.
It responded very badly, and the speaker was gone.
I decided to downgrade back to 1.1.1 and jailbreak him again, but that wan't as easy as I thought.

When I restored 1.1.1 with iTunes 7.4.2 I was getting errors like 1011 and my iPhone just woudn't respond anymore. I managed to get it bootup once, but it still didn't responded fast to my input on the keypad.
I decided to restore the phone to 1.1.3 (!), and suprisenly my iphone responded fast and the speaker worked again!

Next thing was getting 1.1.1 again working, in order to jailbreak the device.
I managed to get 1.1.1 restored with iTunes 7.5, got out of DFU mode with Independence and I jailbreaked it again:

From the start:

1. Connect your iPhone to your computer
2. If it doesn't show up in iTunes, then put it in DFU mode by pressing and holding both the Power button and the Home Button. After 10 seconds, the iPhone's screen will go black; let go of the power button, and continue holding the home button until iTunes displays a pop up. Click OK.
3. alt+click on restore, and point iTunes to the 1.1.1 firmware, and let it restore
4. When done, hopefully it displays the emergency screen, if not, eject the iPhone in iTunes, quit iTunes and bootup independence. Let it connect for a while and hopefully the iPhone is getting kicked out of DFU mode. If not, restore again
5. Slide to get to the emergency screen
6. Type *#307# and press Call
7. Now, if your iphone does NOT respond well on your input, and you don't hear the speaker anymore, restore to 1.1.3, and start again fromt he beginning !! (when restoring to 1.1.3, the baseband will be completely re-written, which fixes the encountered problems)
8. press the Back button on top of your screen to delete the just typed *#307#
9. Your phone will start ringing do not pick up
10. Delete all just typed numbers and type 0 then press call again
11. Your phone will ring again now press accept and then press hold
12. Your phone will ring again now press dismiss and your phone will go to the contacts/dial screen
13. Press contacts, add a contact without a name
14. For this contact you now have to add an URL (web adres):
    This has to be exactly: prefs://1F
15. Save your contact and click on the url, you will now get to the Settings menu in your iPhone
    where you select your WiFi and make sure the Auto-Lock is set to Never
16. Restart your iPhone
17. After your iPhone restart the Wifi icon should be back (indicating WiFi is working), if not then repeat step 1-10 again
18. If your WiFi does work repeat step 1-8
19. Now add another contact, with a different namen and with the URL: http://jailbreakme.com
20. Save this contact and
    Go to the URL you just saved (http://jailbreakme.com)
    and install appsnap.
21. Launch Installer.app
22. Install BSD Subsystem
23. Set Auto-Lock to Never
24. Install SoftwareUnlock for 1.1.2OTB and 1.1.3OTB (because the readme says, this can only be installed on 1.1.1
25. Scroll down to Tweaks (1.1.1), and install OktoPrep
26. Connect your device to your computer
27. Launch iTunes
28. Choose your device, alt+click on UPDATE, and select the 1.1.2 firmware file
29. Wait forever for your device to update reboot
30. Close iTunes
31. Download 1.1.2 jailbreakon Mac, double click on jailbreak.jar, on Windows, double click on windows.bat
32. Follow the on screen instructions and be patient
33. Now your iPhone is 1.1.2 jailbroken
34. Install iWorld
35. Done.