lagging audio for HDDVD file

i need your help! i posted this late last night and didnt get a lot of replies, i guess the time was a bit off..

ive just finished downloading mr and mrs smith and now im experiencing problems watching it. size was 13gb so just deleting it and downloading another is not rly going to do!

anyway, the problem is the following. the filename is as follows Mr.And.Mrs.Smith.2005.HDDVD.1080p.DTS.VC-1.Remux-Eureka so as u can see the audio codec is DTS. Now, when i watch the movie, after some time the audio starts to lag which results in it being unsynchronised which ofcource is unacceptable.
yesterday i watched another HD movie which gave me the same kind of problem for the video part of things. i fixed that by downloading coreAVC and adding that to external filters and setting it to prefer. so now i can watch these movies fluently for as far as the video is concerned but now the audio is proving to be a problem.
Note that the audio runs smoothly everytime for about 20 to 30 seconds and then it starts to lag and fall behind again.

If anyone can tell me how i might be able to fix the audio so that it will run smoothly again in WMPC then pls lemme know what to do. google hasnt been of much help im afraid

thanks to those who already tried... it didnt quite help yet though. The GOM player doesnt play the audio at all and makes the video lag as well.. also, ive been able to play other 1080p HD files without any problems already.

specs are

Toshiba Satellite a100-803
screen size 15inch
intel core 2x 1.60Ghz @ 1014MB
32bit OS windows vista HomeP
onboard sucky video chipset thing 128mb

i use mediaplayer classis with coreAVC codec which as said, makes the video play smoothly but makes the audio lag and stay behind.

PLS HALP