Sim not working

[Raffles]

I allowed my iphone to upgrade from 1.1.4 to 2.0, (Which I forgot I
should not do) I then followed the steps to down grade itunes to
7.5, reinstall 1.1.4 and then used Liberty to jail break. the phone
recovered all execpt does not pick up the GSM carrier when the Sim is
inserted.

I have also trid Zphone and used its options to try and resolve this,
each time getting back to full fuctionallity except for no provider
showing.
I have tried to reset networks in settings. one suggestion is that
perhaps the IME code has been locked out? is that possible and is
there a workaround?

Thanks in advance