Why is iTunes 10.6.3 duplicating all my movies?
All of a sudden, iTunes is duplicating my movies. The duplicates are appearing in the same folder with the original, but with different cover art, and an "HD" symbol after the name. This is taking some serious hard drive space, which will run out before it gets very far. This is going to be a pain to fix, especially as I've chosen my cover art carefully, from old movie posters, etc. So, why is this happening, and how can I remedy it, aside from not using iTunes?
Mac mini, Mac OS X (10.7.4), external WD Element 2TB HDD