Is my computer dropping frames? Video sometimes jump!

[Green_Hornet]

Hi!
Well, I'd really appreciate your help with this issue.
I have a problem playing ANY video on my computer.
Doesn't matter the format: Divx, Xvid, Mpg, Asf... it's all the same.
The specific problem is that, sometimes, during playing, there are some "jumps" in the image. For a second or two, video plays 2 or 3 times faster of what it should, so I miss details or dialogs.
Strange thing is that I've played with every possible codec and every possible player. Installed k-lite codec pack ONLY with the codecs I knew I use. Didn't work. Installed ffdshow... same. Instaled k-lite codec pack AND ffdshow... same. Installed nero video decoder... well, you know the answer. Installed standalone xvid decoder... same...
Played my videos using WMP 9, WMP 6.4, WinDVD, Nero showtime... SAME!!! :@ Reinstalled nvidia detonators, installed OLD detonators, installed LATEST detonators... No use.
Btw... in the video renderer statistics, it allways says "0 dropped frames"
Can't think any more solutions...

Help, please!!! Dunno what to do. I'LL REALLY APPRECIATE ANY OF YOUR HELP!!!

Thank you.

[MOVIEGEEK]

Does this happen when you play them on your standalone?Burn a S/VCD or DVD on a RW disc.
If it doesn't it could be several reasons:bad HDD,bad videocard,DirectX is corrupted,DMA is disabled,codec conflict,etc.

[Green_Hornet]

Well, this doesn't happen if I play the movie in ANY other computer. At office is just fine. I've tried in a couple of friend's computers and they work just fine. The problem is only with my computer.
Checked hdd for errors, and made a full diagnosis using Sandra 2004. DMA enabled, erased all codecs and reinstalled one by one.

What else could I do?

[Grapeape]

If you have an onboard audio card, disable it and put in a generic soundblaster generic card or whatever. It worked for me.

[Green_Hornet]

Thanks, but I'm using an Audigy 2, no onboard audio.
Still the problem