When my N80 has an 02 pay-as-you-go sim card in, I get a "General: System Error" every time I try to read an SMS message. This effectively hangs the phone and I have to remove the battery to stop the beeping and carry on the error causes.
If I put in my Telstra sim card, then there is no problem (even with the same messages).
I used the Nokia Software updater to confirm that the firmware was current (it is) but tried reinstalling it all anyway, which made no difference.
Any clues as to what I can do to correct this problem? My N80 was purchased in Singapore, and is not under contract to any UK service provider.