Vista Windows Photo Gallery Shows Video Too

This is probably old news to most people. But, I only noticed this evening that the Vista Windows Photo Gallery displays videos as well as still images. Yeah, doh. I usually work on my family photos on a old Windows XP PC because XP on the old PC seems to run faster than Vista on a newer PC. In fact, even simple things like list files in Windows Explorer seems much faster on XP than Vista.
I have an old Celeron based XP PC with 1GB RAM in my office as well as a relatively new(ish) Core 2 Duo notebook running Vista with 2GB RAM. Vista seems to take forever just bringing up a list of files while XP (on a Celeron) is pretty fast. At home it is an ancient Athlon 32-bit box running XP and a slightly less ancient Athlon 64-bit box running Vista (32-bit).
In any case, if you are running Windows Vista and have a mix of still photos and videos in a folder (I keep all files from my digital camera, still and video by month to ease backups to DVD+R discs), double click on a still image near a video file (AVI in my case) to bring up Windows Photo Gallery. Then, press the forward button to move from file to file. The video should start playing right in Photo Gallery after a few seconds delay.