well, i have dug around a bit and have not found anything that will directly convert from .mov to .avi. Though, if you really wanted to get it to that format, you could convert it to a raw format, then use an avi tool to convert it to .avi. If you search freshmeat.net, there are plenty of apps that convert to a raw format, then you will have to find another for the raw to avi format. heh, just nothing that converts from one to the other in one motion.
btw, are you having an issue playing the .mov?