Kenny, I have the same problem. Is your iPhone Jailbroken/unlocked? Let's try to identify the similar properties, it will help when someone figures out a fix. I've heard around that 3.1 should have this fix and that this issue is most likely software related.
It all started on 2.2.1, out of nowhere, the Wifi was lost. Still dont know how, but ever since, I've restored and pretty much did everything I read aroun. (Even the freezer, but no success)

I'm still on the lookout for a solution, and as soon as I find one, I'll post it all over so that people like us don't spend months trying to fix this damn bug.

Good luck, please let us know of any updates.