5005 problem

Folks:

I got a 5005 last year, it worked well at first. Two monthes
ago, it started having problems. 1, It cannot play back the discs
it created, finalized or not, even those created before. But the
discs it created can be played on other DVD players! 2, When
I copy sth using it, I have to finish the copy at one time and
finalized it, otherwise it will not be able to read it later. I guess
problem 2 is associated with problem 1.
I tried to upgrade the firmware to 1101 but did not solved the
problems. I am very glad to find this forum and see many high
hands here. Does anybody had similar problems or has a
suggestion what I should do?

Thanks!