3gs Jailbroken using BlackRa1n - Can I upgrade

[residualboulders]

I have a 3gs on firmware 3.1.2. I can't get my picture messaging to work, they are always rejected. I read somewhere that someone else had this same problem and solved it by upgrading to 4.0. Anyone know how to do this on a phone jailbroken by Blackra1n?

[iYeow]

Do you need an unlock ?

[residualboulders]

i have it unlocked using blackra1n. I have cydia installed on my phone I am using firmware 3.1.2. I can't get picture MMS to work. I can send images, but i cannot receive. I'd like to just get it working.

after researching all over, and trying many solutions i can't get anything to work and tmobile is no help. I read a post someon emade indicating that they upgrade to OS4 and was able to get it working again.

I'd love a fix using what I have. If not, does anyone know how to upgrade from my current settings to os4 that will allow me to use my phone on tmobile with data, internet and picture messaging

[iYeow]

Then what you need is to restore to a custom firmware of 4.1 created by Pwnage tools 4.1.2. If you don't have a Mac, get this custom firmware from someone or from the net.
Download Redsn0w 0.9.6b2 or 0.9.7 ( not to jailbreak but to put your iphone into a special DFU mode ) , then Shift + Restore to the Custom Firmware created by Pwnage tools 4.1.2.