Problem...with movies

[aegis]

Hi, i have the following problem:

When a try to view some movies from my portable disk , bs player reproduces them , but only the sound is working and in screen i get stange color lines....

If i copy the movies on the hard disk bs player plays them normally....
Also media player plays them normally from the portable hard disk as well...

I should note here that bs player didn't do that from the beggining....
But reinstallation didn't solve the problem....
Also i doesn't do it with all movies...{although they have the same encoding}

Is there any known conflicts with vlc, winamp or media player that i also have installed?

any help will be appreciated...

I have attached an image showing what i am experiencing...