[Resolved] Problems with my external USB2 disk

I have an extrenal Lacie 250gb usb2 harddrive. I'm using it to store my music and movies on, because they won't fit on my tiny 20gb laptop hdd. Until just recently I used to watch moves and listen to the music straight from the external disk, but I can't do that anymore :(
The movie/music works fine for a few minutes, but then it stops. After 10-20 seconds it picks up again and starts playing for a few minutes untill it stops again.
I get the same behaviour in both Windows XP and Linux (Ubuntu Hoary).
I've run scandisk on it (took about 6h to complete *yawn*). I didn't get any errors.
What could be wrong?
Is there anything I should try?

Thanks in advance
//Tobbe

Have you installed any software lately like a virus scanner or something?

hmm, not in Linux. I do have a virus scanner in windows, but it's the same as I have always had. I'll try watching a movie without it and see if it helps

I think I solved it. Your idea led me in the right direction.
The villain in this case seems to be MySQL. As soon as I kill it the movie playback returns to normal.

Thank you