nokia 7710, blocked up and closing program , don't start program

Hi all,
sometimes, tomtom isn't start and bluetooth don't get the connection:
they start when I turn off and turn on back the telephone.
And sometimes, the pdf+ turn off when I reading a page: if I turn on
back, it automatically goes at the last page and sudden, it turn off
and not allow to continue the reading.
There's an answer??

However it is wonderful, then you don't try to tell me to change
telephone!!
Bye Bye
markus