Cannot rename video file in iTunes.

I have converted some movies to mov files and renamed them in windows explorer. When I import them into iTunes, it retains an old name (like movie 1_5 or some other useless title). When I try to rename in iTunes library, it just keeps reverting back to the old name. How can I fix this to match the name I gave it in Windows Explorer?
This only seems to be happening with my movies and not my songs.