iPhone Jailbroken HELPPPP

[tigerstyle]

Hello everyone,
im a new JAILBROKEN 1.1.4 iPhone owner. This jailbroken iphone is off the hook specially with all the apps from this freaking sweet site!!!

Well im kinda stuck right now... i need to know a few things...

First of all is that, ive jailbroken it and unlocked it via ZiPhone 1.1.4 like 4 days ago... and i heard that if you do that, you can swap your original sim with any other carrier's sim and your jailbroken iphone will still work.
Today at work, i changed my original sim (AT&T) with another sim (T-Mobile). when i turned it on, it couldn't find no service so i changed the sims back.

So my question is, what do i have to do so my iphone will work on T-Mobile sim instead of its original sim (AT&T)? Please helpppp o0o0o0o

[Safari]

Well make sure the SIM is activated and paid for first, and make sure its registered to you. Also, you could re-unlock with the SIM card in it if that doesnt work.

[tigerstyle]

re-unlock the SIM card in it? Do i need to install a patch or something?