Vista - Problem with sound in ULead Movie Factory 4

I've installed Vista and then installed a fresh copy of Movie Factory 4, with
the latest updates. The app works better than Roxio's Creator 8, but I do
have a problem with no sound when I load an avi or mpg file into the DVD
editor to begin working with the file. The same file plays in Windows Media
Player with sound and it also plays with sound in the DVD player that comes
with the ULead app. But there is no sound in Movie Factory itself. MF will
play sound with a wmv file. Anyone else have this problem or a solution? It
is difficult working with a program when there is no sound. (I have reported
it to MS and will see if I can let Ulead know about it. I don't know what
there policy will be for support of Vista in older apps, however.