[SOLVED] Stripes in movies!

[pilz]

BSplayer PRO: 2.40, build 997 17 april 2009
Windows XP
video card: Club3D HD 4650 512MB GDDR2
monitor: Dell 3000WFP 30"

When I play a movie with BS Player, i see white stripes moving on the whole monitor, like when you watch a very old movie in the cinema! Since I had a new monitor, I still got warranty and today I got a new one, but still the problem sometimes exists. I tried to change different options but nothing really works. However if I resize the video screen to veryyy small I don't have this problem. Is it something about my monitor or video card, or can I fix it with BS player?

I made some home-made movies of this problem, downloadable through: Mega-upload - stripes

Thanks in advance!