Avi's. some play, some don't..WTF?

Hey! Dumb newbie question here.
I’ve downloaded thousands of avi’s over the years of all kinds of stuff and occasionally one won’t play. Well it does play but it plays some trippy visuals and I can hear the sounds of the avi. What causes this? How can I correct it?
I know others are seeing it because some avi’s will have comments left by people who have seen it. I use windows media player, irfanview and VLC media player. Windows media player gives me the trippy visuals while irfan and vlc give me a black screen. I don’t get any error messages or messages telling me I need certain codecs. I’m fairly certain I have most of the codecs, when an avi won’t play in irfanview it usually tells me which codec I’m missing and I’ll go and download it and it plays fine. But like I mentioned occasionally I get a black screen. Any clues?

Problem is likely due to the source of your downloads…

[QUOTE=harley2ride;2273932]Problem is likely due to the source of your downloads…[/QUOTE]

Exactly what i was thinking. :iagree: