Laptop TV Out Problem - Help!

Hi All

Lately, I have been getting a problem with the TV output from my laptop. I
use it for viewing DVDs and sometimes .avi and .wmv files on TV, and
normally the image on the TV screen sizes itself automatically when I use a
DVD player or Windows Media Player 9 (I use the clone command in the NVidia
Settings window to get my desktop display to the TV, and normally the
display switches to full TV screen when I play back a video or DVD).

At some point the automatic resize-to-TV stopped happening . The first time
this occurred, it happened only with Windows Media Player. I wound up
reinstalling XP, and the problem went away.

Unfortunately, the problem has returned, though this time I get the problem
with PowerDVD as well. I'd really like to find a fix which doesnt involve
reinstalling XP .

My system:
Dell Inspiron 8200, 2.2GHz, 512MB RAM, 40G HD, GeForce 4 Go, Win XP.

Any suggestions? Or any suggestions as to where to go to find help?

Thanks,
Chris