on TehC, why do most xvid films contain 2 AVIs - cd1 and cd2? I looks like both file sizes are about 700MB each, is it just 2 versions of the film for some reason?

NO not only in TC but every where (look ipt & TL) search for the movie you will see the same
it is the original scene content
it is made that way by the original encoders

and NO the 2 cds together = a single movie .

ah ok, thanks for clearing this up. I just found it a bit odd since nearly every xvid movie I had seen before was roughly 700mbs with only a single file.

That's because they were using shittier resolutions. If you see CD1, CD2, sometimes even CD3, it's a just a better/higher resolution that can't be achieved from a DVD source. Most multi-folder scene releases over 700 mb are xvid or x264 encodes using a bluray source. Ripping a bluray down to a file size less than a GB is pointless, mind as well just rip from a DVD. You see?