strange playback problem (audio video synch and random skips)

[aMX010]

I have two problems concerning digital video playback on my system:

1) audio / video out-of-synch
The audio stream gets out of synch after watching a video for a while. This gets worse and worse the later I am in the video. Stop and Resum does not fix this.

eg: Fight Club AC3 2CD DVD Rip

2) audio / video skipping
During playback the video all of a sudden skips a few seconds in fast forward and recontinues playback from there. Sometimes the audio gets out-of-synch after the occurance.

eg: Enterprise Season2, Dark Angel Season2

* These problems occured on my system afterI installed and immediately uninstalled the NIMO codec pack lite.
* I installed and reinstalled NIMO 8 various time with all kinds of different options set.
* Also tryed divx3.11a and 4.x (which won't work by themselves though for some strange reason, errormsg: unknown compression: DIV3/DIV4 or something)
* The problem occurs on various players (WMA, BPLAY, WinDVD, PDVD, etc)
* It happens with various video codecs (divx3/4/5, ac3, mpeg2)
* Video is played back from HD
* DVD Playback works fine, so does RM
* Smaller videos (trailers etc) run fine too.
* The video files cannot be the source since they run fine on a different system

My System:
P4-1500
512mb SDRAM
Asus GFX / nVidia Geforce 2 GTS
8x DVD ROM
HD UDMA enabled
Win2k SP3

I was able before to playback all kind of videos smoothly on the same system under win2k and winxp (both installed prior to the current win2k).

I would really appreciate a hint what the problem could be and how to fix it.

[Enchanter]

1)
Try the following fix for off-synch audio:
1. Load up AVI file in Virtual/nandub
2. Set both Video and Audio tabs to Direct Stream Copy
3. Under Audio, go to Interleave and input the appropriate value in the 'Delay audio track by x ms' box
4. Go to File -> Save as AVI and give a name to the new file

In the case of the audio gradually getting more and more off-synch from the video, add the following step prior to saving the file:
-. Under Video, go to Frame Rate and select "Change so video and audio durations match (you should see a value similar to the original frame rate).

2)
Try uninstalling Nimo and going with Tsunami instead, keeping in mind to install ONLY those codecs that you know you need and unticking the rest.