I have a problem that only seems to affect .avi files. Every time I play one, doesn't matter what it is, it will pause for less than a second then fast-forward to catch up to its true position. This will happen through out the entire playback about every 10 to 20 seconds. This has only started to happen recently, like within the month, could have started last month but I really don't remember. I've been assuming it's the codec. I deleted it and reinstalled it twice and I still get the pausing, then again I don't have enough knowledge about this stuff to really know what's going on. I'd appreciate any help because this is getting really irritating.
Try playing it with VLC instead of Windows Media Player. It has it's own self contained codecs - doesn't rely on the system codecs and can be easily uninstalled if it doesn't help. http://www.afterdawn.com/software/video_software/video_players/vlc.cfm
Actually I use DivX video player so I should be using their codec. I have noticed though that if I don't have anything else running like IRC or Azureus than I don't seem to have a problem. But that still is contrary to what it was about a month ago. I'll check out that VLC program though and see how it works, thanks.