Video About the KH videos' WMV format

I was wondering if anyone has had this occur to them and what they might be able to advise.

After downloading various KH videos from here and having them on my desktop, I thought it might be nice to put them on to my PSP so I could watch them on the go. The only thing is, the PSP doesn't appear to support the WMV format.

No problem, I think to myself. All I need to do is simply convert the files to another format.

So I've been spending this weekend attempting to do just that. There's one problem, though... every time I try it (and this has never happened to me before with others I've tried this with), the sound is just fine but the animation is "stretched" longer than the soundtrack. In other words, the animation is slower, and it grows more and more noticable as the video plays, of course, since it gets more and more out of synch.

I've tried using some three different converting programs and at least three different formats on each one, but always the same result. It's quite the odd situation, as I've never had this occur before and am unsure how to fix it.

Has this occured to any of you, and if you were able to fix it how did you do it?

Any help would be appreciated, thanks.