Invalid Sim Problem

[EuroDub]

Yesterday i decided to update an app that was downloaded through itunes.

I lost connectivity with my provider and was only able to regain it once since last night.

The phone currently tells me its an invalid sim card, and ive tried another sim from the same provider which in turn that didnt work either.

The phone is jailbroken and unlocked(3.1.3)

Any ideas on what i could do?

[i.Annie]

If rebooting your phone doesn't fix the issue, you might have to restore (if possible).