I'm a proud owner of an 8GB iPhone (brought it home from the US last week). A friend unlocked it for me and it runs sweet ... with just one hitch. Every time I hang up a call the phone loses network coverage for a few seconds and I get this annoying message telling me the network is lost and do I want to search for another one. A mate of mine who also brought back a phone that was unlocked by the same friend and uses the same carrier (Telstra) does not have this problem. Weird.

Could be an issue with the unlock, or the hardware

I suggest a restore, but this may revert the phone to a locked state whuich you can resolve using the software hack.

I hold no responsibility for anything that could go wrong or any factual errors.

The SIM unlock processes (both hardware and software, but not TurboSIM etc) make changes to the baseband radio firmware code in order to bypass the SIM checking process. It seems likely from the symptoms you describe that the baseband radio firmware has somehow become corrupted during the unlock process, which seems to happen in some cases according to various reports across the net.

Some people have had success resolving baseband issues by re-unlocking their phone, which in some cases appears to re-write that which was corrupted, though I've not done that myself so I can't say whether attempting a re-unlock will fix the problem, do nothing or brick your phone.

If (when?) Apple update the baseband code in a forthcoming firmware update, and the various unlock processes are modified accordingly, you might find that the upgrade & unlock process also removes the issue again as a result of rewriting the baseband code.

Sorry if that's not much help!