Dolby Digital Skipping with Turtle Beach Micro, Fixes?

[Snuffy2]

I'm running a Turtle Beach Micro USB Sound Card on my HTPC Machine running SageTV.

I have been tweaking this setup for a few month now and I am still having a problem that I can't seem to resolve. I was wondering if there are any guesses on how to help resolve this (although I'm not really sure what exactly the issue is).

Anyway, this problem occurs with NVidias Purevideo Audio Decoders, AC3Filter, ffdshow and every other decoder I've tried.

It also occurs in WMP 10 & 11, SageTV, VLC, Media Player Classic, WinDVD 7, WinAMP, and any other player I've tried.

When I output PCM 48 audio over the optical connection, everything works fine. When the output is Dolby Digital, there is skipping of the audio file sporadically. The skipping is at least every 10 seconds but is not regular.
Also, if I rewind and replay the same section that skipped last time, it may or may not skip the next time.

So why is the Dolby Digital output causing this skipping? Any ideas on how to prevent this?

I'm currently stuck at 2 channel output from my HTPC if I don't want skipping, which is a waste of my 5.1 setup.

Thanx

Setup is:
Win XP SP2
Dell 4700
3.0gHz Intel PC
1.5gb RAM
nVidia 7300GS hooked up DVI-HDMI to Pioneer Plasma TV Turtle Beach Micro hooked up via Toslink to Sony Receiver