Corrupted QuickTime movies are very difficult to recover. You may have some luck with Digital Rebellion Pro Maintenance Tools:
which contain Corrupt Clip Finder and to help track down corrupt clips and Media Salvage to try and recover the files from the corrupted media.
Don't just by one disk drive, by enough so you can keep complete back up copies of all your media. This is/should be SOP for working on large or consequential projects.
I did keep the original video files on separate hard drives with additional backups. The files were then converted to ProRes, which are kept on these two editing hard drives. I probably should keep backups of these editing drives, but if need be, I can go back to the original files and convert back to ProRes. It would be really cool to fix whatever is wrong with this drive though! Thanks for the tip on the digitialrebellion site.