MKV stuttering

Hi all. I have the latest firmware 1.10. I can play all file types via Twonky just fine with the exception of MKV which stutters and pixelates terribly. Can anyone help? The main reason I just bought this thing was so that it would play MKV files!!!

Cheers

Please post the full TEXT output of MEDIAINFO for such a file.

http://mediainfo.sourceforge.net

Er… how do I do that?!

Download and install the program.

Open the video file with that program.

Switch the View to TEXT mode.

Cut & paste the info.