If the footage is already compressed, it's too late to save them as uncompressed files. That's why we don't support downloaded footage here. Try opening the episodes in VirtualDub and saving the clips you want as huffyuv or lagarith. Otherwise, you're stuck editing with a buggy codec.
To slow them down - add the clip to your timeline. Then you use an effect (been a while, so this might not be perfect) - try right-clicking the clip and see if that gets you the effects list, if not, there should be an 'effects/transitions' box on the left side of the program. The effect you want to use will say "slow down by half" - click that. Add the effect at least three times and you should see every frame in the clip - that will let you find those spare frames and cut them out. After you've cut out the spare frames, you can remove those "slow down by half" effects - then your clip will be back to its natural speed.
Or you can take your finished video file, open it in Virtualdub, cut out the spare frames, and save the video without them. If it's a just a few frames here and there, it shouldn't affect your sync.
...if it's more than a few spare frames, if it's actual *clips*, then yeah, an example would be good.
If you've never heard of VirtualDub, you should read the "all things audio and video" guide:
Even if you never rip your own footage, vdub's a really handy program to have.