MKV format

First off, i am using a P4 2.0 Ghz, 768Mb's RAM, and an Nvidia 256MB vid card. Now I have been having issues with getting mkv files to properly play on my system. Over the course of having this issue I have tried a few different distros and have had the same issue in all of them...Currently I am using LinuxMint Elyssa 5 Xfce. The audio seems to play fine, and the video goes out of sync. I have tried it in Mplayer, Xine, and VLC and they all ahve the same issue. The ideo plays slow... I am at my wits end with this and no longer have an idea of what i should do to get them working. I would stop using the MKV format, but well the stuff I am watching is released in that format. Any ideas or what other info would you need?.

i would do a google search for "video benchmarks" and run one on your system to get an idea of what performance you should be expecting out of it. if the sytem you are on has an odd motherboard it is possible your problems are rooted in hardware. its not an area i'm expert in hence the vagueness of my reply :-) i know people get issues playing some formats on odd hardware like mini-itx boards. other than that i'd recommend trying it on another machine and comparing those..