Only some MKV files working on Xbox as extender.

Hey.

I have searched and trauled the web and this website for answers and this site seems to have some pretty good responses so i thought i would post here. (I have also made a post on Shark007 fourms)

I run windows 7 ultimate 64bit on Intel quad core, 2gb ram with nvidia geforce 9600gt.

Starting out with no idea what to do, after a some fiddling and searching i have now got both shark's codecs installed (normal and x64bit) and can run some MKVs through Windows media center using my 360 as an extender.

However, on about half of my MKV files i get the error message:

"The file type is not recognized and cannot be played. Either the correct coded is not installed or the file is corrupt" when trying to play on the xbox360. These same files play fine on Windows Media Center and Windows Media Player on the PC however.

I have tried various settings and also divx and CCCP codecs packs with the same result, (although i had to change some stuff in regedit to get MKV to show up on the xbox using divx) but in all honesty i don't really know what im doing and would really appreciate any help or suggestions you can give.

If you need any more information feel free to ask.

Thanks for reading and thanks for your time.


Edit:
I have noticed using sharks analyze function that the MKV which play are:
"Format settings, ReFrames : 4 frames"

and the ones which do not work are

"Format settings, ReFrames : 5 frames"

I have no idea what this means but maybe someone smarter than me does here.