Hi there Here's a page with tips for you:
http://www.deskshare.com/Resources/a...owerPoint.aspx

According to this article, the WMV has to be the same resolution as the PPT in order to look good.

Another option is to just bring the JPEGs into PPT and use an animation transition between them, instead of video. It will look better, of course, but I imagine that file size is your reason for using WMV.