Whatisk:
I came to that conclusion since I did an extensive search on google using any combination of: video, judder, micro stutter, HTPC, SPDIF, DTS, MKV, MediaPortal, Mediacenter, Reclock, Refresh rate, NTSC.... and maybe a few others.
My final conclusion is so far that the judder/"speed up" occurs on NTSC-film/24fps (and maybe PAL/25fps) using SPDIF pass through with DTS. Apparently some of the websites I came across mentioned a bug in DirectSound, which has the unfortunate side-effect that DirectX is not capable of resampling the DTS audio equivalent to the "reverse 3:2" (from 24fps to 30fps to match 60Hz display).... or something like that.... but the result is that my sound goes perfectly, however my video tries to catch up every 20 secs or so (haven't counted seconds though)..... And no, it is NOT my system (I will just update my system specs now, so you can see it).
If you are able to, then please try to use WaveOut as your output. However, you will probably get A LOT of stutter and choppy sound and slooooow just like I got.
I haven't tried Reclock yet, however they mention potential problems using SPDIF. It is however 50-50 out there it seems.
My problems started after a switched from analogue mini-jacks to SPDIF pass through.
BTW.... whatisk.... I would recommend upgrading MP from 0.2.3.0 and maybe in general update your system specs in here ;-)
Thanks for the feedback. Every MKV I tested that had the judder was 24FPS with DTS. And yes, I get the same as you, perfect sound but the video speeds up for a split second at regular intervals.
I will give WaveOut a go and report back. I have been looking at Reclock also and gave it a quick try last night. I had no luck at all with it though
As to the system specs, they haven't changed (well, except I'm no longer using Purevideo - FFDShow instead). I'm looking at upgrading to MP1.0 probably on the weekend. I currently have 0.2.3.0 running just right - well except for this MKV with DTS judder issue, but an upgrade to MP doesn't sound as though it will fix it. When I upgrade I'll be starting with a fresh build and so might try K-Lite codec pack that others have said seems to fix it. I'm not too sure how it would as I believe it just contains what I have already along with perhaps a couple of other codecs. Though I generally try and avoid loading them if at all possible.
Australia