3.1.3 Unlocking issues

[doeboynmek]

I used to have T-Mobile only, so when I unlocked and jailbroke my 3G it was a breeze.

I just bought a 3G through AT&T and activated it through them.

I upgraded to 3.1.3 and kept my baseband at 4.26.08
and installed ultrasn0w

However when I put my T-Mobile sim it says different sim detected

I don't want to restore and hacktivate because then Push notification won't work, is there a fix for this?

[neodude237]

Have you gotten ultrasn0w through cydia?
(I assume you had restored to do the official activation, correct?)

[doeboynmek]

Yes I am, and I restored with a custom IPSW made with PwnageTool without hacktivation, it activates with the ATT sim, I take out the ATT sim, install ultrasn0w through Cydia, and when it reboots and i put the T-mobile sim it automatically goes to "Different sim detected, please connect to iTunes"

and of course when I connect to itunes it says it isnt a valid carrier