Possible to Downgrade Baseband? No Signal on my iPhone 3G!

[Chiitus]

I accidentally upgraded my iPhone 3G to 3.1 using iTunes 9. This made it go to DFU mode instantly. After restoring to 3.0 and Jailbreaking with redsn0w, I notice that it can't find my operator.

I can't use any phone related services, obviously, but the signal indicator say that I have 1 bar of signal, but neither the Edge or 3G icon won't show. Also, the phone operator's logo is gone.

I know the Dev-Team's blog post clearly say not to upgrade to 3.1 as it updates the baseband, making it impossible to unlock. However, I do not need an unlock because I am using the SIM-card which I got with the iPhone 3G.

If there is any way to fix this now, or if the Dev-Team will fix this in the future, anything, please tell me. Will the PwnageTool 3.1 give me back my signal?

I can not return the device because I do not have any proof of purchase, neither any kind of AppleStore in Norway, nor iPhone repair merchant. I'm desperate.

Any advice will be appreciated, thank you!

Edit: I forgot, I've also tried to unlock it using ultrasn0w, before posting this. No difference, at all.

[blkcadi]

Even tho you don't need the unlock try adding the ultrsn0w repo for the unlock it may work. repo666.ultrasn0w.com

[defmute]

Advice: Read the dev blogs before upgrading if you require your phone to be unlocked.

Granted this advice doesn't help now, but that is pretty much the only advice that anyone can give you now.

[Chiitus]

Even tho you don't need the unlock try adding the ultrsn0w repo for the unlock it may work. repo666.ultrasn0w.com

I tried, and I don't know if things got worse or better.. At least it's not fixed, tho. It does not say that I have 1 bar, but rather just "Searching..."
Is this good?

Advice: Read the dev blogs before upgrading if you require your phone to be unlocked.

Granted this advice doesn't help now, but that is pretty much the only advice that anyone can give you now.

I do not require my phone to be unlocked. I am using the operator whom I bought the iPhone 3G from.
And this was an accident. Kind of. Not on purpose, anyways.

[smirkis]

you have the new baseband, on the old firmware = no service

you need to jb 3.0 using redsn0w or whatever, then get a custom 3.1 firmware and shift+click to upgrade to 3.1 after its already jailbroken. only upgrade to the custom firmware after you are already jailbroken on 3.0.

after u do this, you'll be on 3.1 jailbroken, not unlocked, and get service from your official carrier

[Chiitus]

you have the new baseband, on the old firmware = no service

you need to jb 3.0 using redsn0w or whatever, then get a custom 3.1 firmware and shift+click to upgrade to 3.1 after its already jailbroken. only upgrade to the custom firmware after you are already jailbroken on 3.0.

after u do this, you'll be on 3.1 jailbroken, not unlocked, and get service from your official carrier

THANK YOU!
I have 3.0 Jailbreak so I guess the remaining step is to [shift]click restore to the new 3.1 custom.
But where can I get a custom 3.1 firmware for my iPhone 3G?
Do I use PwnageTool for this?
I didn't really get that program, I think.
Kinda n00b to the whole baseband and jailbreaking processes...

I don't have a mac so I can't use PwnageTool to make a custom Firmware 3.1 which I need to get my signal back. Tell me if I'm wrong, tho.
So can anyone give me a Direct Download link to a 3.1 Custom Firmware from PwnageTool for the iPhone 3G?
Thanks!