P800: phantom new SMSes

Hi

My p800 has decided that I have 2 new SMS messages, but when I go into the
SMS program it shows me all the old messages but no new ones.

I've tried powercycling but it's made no difference.

I'm still on the old version (R1D) of the firmware (not been bothered enough
to take it in): is this a known bug?

Just to top it off, as I typed this the phone has decided to display "no
network" even though I can still call out and receive calls (and GPRS is
listed as "attached").

Should I be getting worried?

Cheers

Geoff