AC3 stream in MKV not recognized?

[l3pyr]

I backup my DVDs onto my HTPC by simply demuxing the main movie video/audio and remuxing into a MKV. I don't need to reencode because space isn't an issue (600GB RAID array) and I'm doing it mainly for the convenience of not having to change discs. Anyways, for some reason the AC3 tracks in my MKV containers are showing up as Unknown/WaveFormatEx in Zoom Player's output graph and are defaulting to an audio decoder I don't want to use. If I open the MKV file in mkvmerge or mkvinfo the audio stream shows up as AC3. Audio/video remains in sync during playback, and SPDIF still works fine, but it's bugging the hell out of me because I can't figure it out. I'm using Haali Media Splitter. Any ideas?

[l3pyr]

Some people might find my batch file for doing a one-step backup from DVD to MKV interesting, so here it is. I use AnyDVD and demux straight from the DVD but it would easily work with decrypted files on the hard drive. All you have to do is drag the first VOB file of the main movie (like VTS_01_1 not VTS_01_0) onto the .bat file and it does the rest. Even sets proper audio sync and names the file accordingly. It defaults to track 1, which usually works. If you need it to use a different track just change the value of -TN=1 to whichever track it is on the DGIndex options.

Begin Batch file:
@echo off
echo Starting project on %date% at %time%
echo:
echo Demuxing DVD Movie...

"C:\Documents and Settings\All Users\Documents\Applications\Video Encoding\dgmpgdec148\DGIndex.exe" -TN=1 -OM=1 -AIF=[%1] -OFD=[RM_Project] -EXIT

echo:
echo DVD Movie Demuxed!
echo:
echo Project Details
echo ---------------

dir d: | find "Volume in drive" > name.txt
for /F "tokens=6" %%i in (name.txt) do set name=%%i
del name.txt

for %%f in (*.ac3) do set audio=%%f
for %%f in (*.m2v) do set video=%%f

echo %audio% > delay.txt
for /F "tokens=6 delims=. " %%i in (delay.txt) do echo %%i > delay.txt
for /F "tokens=1 delims=m " %%i in (delay.txt) do set delay=%%i
del delay.txt

echo PROJECT NAME: %name%
echo AUDIO INPUT: %audio%
echo VIDEO INPUT: %video%
echo AUDIO DELAY: %delay%ms

echo:

"C:\Program Files\MKVtoolnix\mkvmerge.exe" -o "C:\Documents and Settings\John\Desktop\%name%.mkv" --sync 0:%delay% -a 0 -D -S "%audio%" -d 0 -A -S "%video%" --track-order 0:0,1:0

del "%audio%"
del "%video%"
del RM_Project.d2v

echo Project finished on %date% at %time%

pause