Hrm... sounds like it also could be something with the codecs. Check out TV Nihon's page for the links on how to set them up: http://www.tvnihon.com/help_playback.html

I had a problem with the sound and the videostarting to play out of sync for a while early in 2005, until I saw this.

If not, it prolly could be that your older PC doesn't have the processor speed/memory and proper video card to handle the episode encodes. (hopefully not, cause that would suck!)