Well after a few days of messing around and hair pulling I have finally got MKV files streaming to my PS3 with the AC3 audio working correctly.
I originally followed the OP’s guide, uninstalled my xvid, divx, and ac3filter codecs and installed vista codec pack, which then allowed me to view my mkv files in WMP, then installed tversity as instructed and created a new user to run the service under, set all the settings as instructed and did all the reboots where instructed.
This got my PS3 able to play the mkv files, however the audio was corrupted, and no amount of setting the right codec in ffdshow or ac3filter would make any difference to this. This was so much better then the corrupt data message I had before though
So, reinstall my o/s from scratch to see if it was any of the old codecs settings hanging around. Still the same problem.
Started to investigate more about how to get information about what codecs TVersity was using, because if I enable the tray icons for the codecs and run the file in WMP i can see it correctly loads FFDShow video, AC3Filter and Haali.
Then I discovered starting the media server in -debug mode, which solved all the problems, and this showed me that TVersity was using the correct codecs (the tray icons appear), however starting it up as a service again and it went back to corrupt audio. Now I agree with a number of posts on here about this audio problem it’s some sort of codec confusion issue.
However, running ‘mediaserver -debug’ is not a viable solution as it has to be done every time you want to use it, and I don’t know what other stuff enabling it for debug does (e.g. slowing it down with additional checking etc)
So, what is different between -debug and the service, one big thing is that the service is running under the new user I had set up, and under debug it runs under my user. Changing the service to run under my user solved all the audio problems and it works perfectly.
It seems that the new user I set up just before modifying the service (as instructed to in the OP guide steps) gets screwed up codec settings. I even logged on as that user and set the codec configs again (they all looked right in the config apps, but just made sure) and it made no difference.
I think what you need to do is to create the new user right at the start of the steps, before all the codecs are installed, in my many test re-installs of my pc over the last few days I did have one of them working with correct audio using a new user rather than my current user, and iirc, i had created the new user early on in the installation, way before the codecs were installed.
So for people that have followed these steps and created a new user account to run the service under and are still getting garbled ac3 audio, try running mediaserver with -debug, if that works then change the user the service is running under to your own user and see if that works.
And if you are following the guide from scratch and intend to use a different user for tversity service, make sure you create the user before installing the codecs!
Hopefully I can save some other people days of messing around that I have just been through