Hi I'm currently running a 3.2GHz HT P4 with 2Gb ram, an 8Mb 250Gb HDD and a 128 6600Gt VGA card. I'm trying to play .mkv HD video but after about 10 minutes into the video it starts periodically stuttering, then it plays again for about 5 minutes etc... The sound keeps playing throughout. Any ideas? Thanks in advance.