US/UK iPhones - are they different?

Hi, everybody,

I got two iPhones here.

1st: UK-iPhone Week 42 - OOTB 1.1.2
2nd: US-iPhone Week 51 - OOTB 1.1.2

They were both just dg'ed 1.1.1, oktopr'ed, upgr'ed and jailbroken. With the same procedure.

If I put my simcard (German T-Mobile-reseller) into the UK-Phone, I cannot activate edge. It tries for a while and ends up with no IP.
If I do the same in the US-iPhone, I instantly get an IP and can use edge.

The only difference I knew of, were the turbosims. So I exchanged them, reprogrammed them and ended up with exactly the same situation.

Why is that I can use edge with an US-iPhone, but not with an UK one?

Thanks for enlightening me.