I'm having trouble playing video (720 & 1080) at 59.94 fps through MPC-HC with ffdshow. After about 20-30 minutes, the audio & video slowly drift out of sync & get worse from there. This occurs when I either use a real-time bob deinterlacer, or if I create a progressive file using a bob during the encode. The CPU is running at about 50% during playback so it's not a bottleneck there. I've told ffdshow to drop frames on delay but that hasn't helped either. Could it be a bottleneck elsewhere? I'm running a Pentium Dual Core @ 3Ghz with an Asus ENGT240/512. Any ideas are appreciated.