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.

No reply from Nokia support on the issue, so I went into an O2 store to see if they would give me a sim card which doesn't have any of the O2 software likely to be causing problems. They got rather huffy about generic handsets and said that their cards were only guaranteed to work on O2 phones.

I tried an Orange sim card in the phone and it worked (at least it didn't crash the phone when I tried to open an SMS).

I should also add that by "current firmware" I mean it is the v4: 4.0623.0.41 which it would appear is available directly from Nokia over the web now.