These problems can occur usually when the phone is out of memory (phone memory runs out). You get numerous errors in the daily operation..

best thing up is you clear up ur phone memory and keep things in mem card and do a hard reset of your cell (if not den a restore factory settings) this should clear ur cell up and den it will be good as new..

try to go 4 a software upgrade, easy one is available on nokia site..use it.. :)