A tech said this is WindowsMedia's or the system's fault, but often after tooltipping or thumbnailing wmv/asf clips, they do not go away when file delete. Technically they do delete (no error), but stay there until close and restart Dopus. Can there be a way to tweak the movie plugin to force close handles to clips when this happens? (Which is often, as said.)
I've seen this as well, not only with Opus but with Windows Media Center. It seems to be a bug in the WMV codec or something related.