Some Movies Not Importing Into iTunes

Hi all. I'm new here but have a problem that I have not been able to resolve through much research.

iTunes 11.0.5, 64-bit
OS X Mountain Lion

I have a bunch of movies that I ripped from my DVD collection using Handbrake. Those have all imported into iTunes without issue. I wanted to re-rip those movies using Handbrake's iPod Touch setting so I could reduce the file size and optimize the video for an iPod. I now have them all re-ripped and when I import them into iTunes, only a handful of the movies actually get imported. I have deleted those and tried to do them all again and only those particular movies get imported, leaving the others behind. On the movies that are successful, I see the progress bar advancing while the movies are being imported. With the movies that fail, I see nothing on the progress bar.

Steps taken thus far to try and resolve;

- I've tried dragging & dropping and File > Add To Library
- I am aware of the Home Movies problem and that isn't the issue
- I do not have iTunes Match so it's not enabled
- I've disabled syncing play counts between devices
- Some of the files names are only 5 characters so it's not a length issue
- No strange characters in the file names
- I have it set to copy the files into the iTunes Media folder

Any other suggestions on what's causing this?

Thanks,
Greg