I see everyone struggling to figure out what program to use, what format to convert to, but we are assuming that the SMC behaves the same always and it doesnt.
I had a vid, 2min 30 secs long, of fallout 3 gameplay I had got from 1up.com. Legit vid, made for Ipods. I use SMC to put on Fuze and when I go to watch it, I get Unsupported Format error. I transfer 4 or 5 of vids from same site, this one among them and 3 work fine, the other 2 which this is one, give Unsupported Format errors. I dont give up, I try again, this time transferring same vid to the micro card which is not a sandisk card, by the by, and finally for no apparent reason it works just fine.
I can transfer an entire library of video podcasts, 10 or 12 episodes, all roughing same length and format and file size, and I promise that 4 or 5 will not work for some unknown reason.
Its enough to make you pull your hair out.