Windows Movie Maker’s speckle dissolve: what were they thinking?
It’s a completely pathological case for video compression. Heck, the official Mac WMV playback component throws a CPU spike on playback and drops to 5fps. It’s that bad.
Madness. And you should see what it looks like after going DV→WMV→MPEG2→DV→H264, too. Yowch.