6600 not ringing when a msg arrives

Hello every body,

I've got strange issue with my nokia 6600 phone, everything is working fine including ringing when an incoming call is coming.

The only probelm is that when a msg arrives, the phone won't play the ringtone, won't even flash its lights, only a symbol will be shown in the up left corner, and this is making me a headache, because I would have to check for msgs all the time. :frown:

would you please help, I tried almost everything including reseting to factory settings, changing the tones, but no benifit.