Need to rejailbreak my iphone 3g 3.1.2

[rehabdirector]

I have an iphone 3g firmware 3.1.2 baseband 04.26.08.
I bought the phone unlocked and jailbroken, but my cydia isn't working and I haven't been able to fix it, so I'm preparing to rejailbreak it. I've been researching on the forums and through google to see exactly what I need to do. I think I am ready to go, but want to check with the experts to make sure I don't mess up my phone.

Based on my searches, I think I need to use redsn0w 0.9.3 to jailbreak and install cydia. I have already downloaded redsn0w and the 3.1.2 custom firmware.

Here are my questions (sorry for any ignorance...I'm still learning):

1) Will the jailbreak effect the unlock? If it does, is ultrasn0w what I need to use to unlock it again?
2) Is there anything I need to worry about as far as the baseband is concerned?
3)Does it matter what version of iTunes I'm using? Can I update to the most recent version without affecting my phone?

Thank you in advance for your patience and willingness to help!!!

[Simon]

All you need to do is restore to a stock 3.1.2 or 3.1.3 firmware (do not use the custom firmware) then use redsn0w 0.9.4 (although 0.9.3 should work too). After jailbreaking install ultrasn0w again. Do not restore from backup when itunes asks you as that may bring back the problem, set it up as new. As long as you dont restore to 4.1 you will be able to unlock using ultrasn0w.

[rehabdirector]

This might be a dumb question, but what is the purpose of restoring to a firmware that I already have? If it is a stock firmware, am I just doing the restore via iTunes?

Thanks!

[Simon]

Didnt you say you are already jailbroken? Jailbreaking again over the top of it (depending on what jailbreak was used the first time) could cause you to go into boot loop and have to restore anyway. Best to start fresh when trying to fix a problem like that. And yes you would use itunes to restore. Just make sure you dont restore to 4.1. Download the 3.1.2/3.1.3 firmware yourself and shift-click restore to that.

[rehabdirector]

Thank you very much!

[rehabdirector]

Sorry! one more question....does it matter which itunes version I use? I have been scared to upgrade, so my version might be outdated. Can I update to the most recent one?

I'm planning to do the rejailbreak this weekend.

Thanks again!

[Simon]

Yes you can update to the most recent version of iTunes.

[rehabdirector]

Thank you.

[CaptainChaos]

What problem are you having with Cydia? I just got a 3G back from a friend that had borrowed it and it still has 3.0 on it. I updated Cydia on it which caused Cydia to crash at the loading screen. After removing a few files via ssh it works fine again.

[rehabdirector]

I tried to remove the files and cydia would open, but then my packages weren't showing and I couldn't download any apps. When I searched for the apps, nothing would show. Does that make sense? :-)

[Simon]

Did you install any updates that cydia had for you?

[rehabdirector]

Yes there were a bunch of updates waiting since I hadn't used cydia in awhile.

[Simon]

Installing all of those updates should have brought everything back.

[rehabdirector]

I think I updated before I lost everything. Unfortunately I can't say for sure. Very frustrating!

I have restored the phone and have had to jailbreak it a few times and cydia still isn't working. I'm getting an error message and then it starts loading data again. Now I'm without my phone because I can't get into cydia to unlock it.

Any ideas what my problem can be?

I restored to 3.1.2. I tried redsn0w 0.9.3 and 0.9.4 and neither worked.

[Simon]

They didnt work to jailbreak or your cydia just still isnt working?

[rehabdirector]

Not sure what I did, but I got it working again. :-)

[Simon]

Glad you got it working