Just wondering....Does anybody know how HDD iPods load their material? Is there anything to read on this? What I mean is this. Let's say I load 10 CD's. Next, I add a movie. Then 10 more CD's and some iTunes downloads. After awhile I take the movie off. Now: what happens to the space where the movie WAS? Does Does iTunes re-load the iPod at that point (after the first 10 CD's), moving everything up, or does it "fill in" only as I add more songs, TV shows etc? I guess I'm wondering how it de-frags....Anybody know?