Premiere Elements 7: Preview playback problems?

[evil-authoress.livejournal.com]

Hello, everybuggy! First time poster, first time video maker, the whole thing. I recently bought Premiere Elements 7, and I'm having trouble with the preview playback as I'm working. The audio is fine, but the video goes in fits and starts, sometimes playing at half speed or not at all, so obviously it's hard to tell how the clips are fitting together. I've tested the source .avi on its own, and it seems fine. Any thoughts or advice would be greatly appreciated!

New Vid: "It Depends On What You Pay" (Dollhouse)

[giandujakiss.livejournal.com]

Song: It Depends On What You Pay from The Fantasticks
Artist: Harvey Schmidt and Tom Jones

Fandom: Dollhouse

Summary: You've come a long way, baby.

Spoilers: Through "Haunted"

Download and streaming info, and notes, available at my LJ and at Dreamwidth.

New Vid: Hot and Cold

[jane-doh1.livejournal.com]

Fandom - Farscape
Artist - Katy Perry
Song - Hot and Cold
Footage - Farscape s1 - 4
Characters - John Crichton/Aeryn Sun
Summary - Some people just can't make up their mind...
Links:

http://jane-doh1.livejournal.com/3645.html