I am trying to import videos to iTunes and having trouble.
I used VideoDrive to convert all the avi files to m4v files, and all of the videos subsequently showed up in a new folder alongside my music folder for iTunes (this had previously been empty).
However, when VideoDrive was processing all the videos, it gave a warning message for each one saying that the "file could not be opened..." and something about "software may need to be added..."
Now, all the movies show up in iTunes, but I can not open or play any of them.
From your explanation, I think that there's a problem with your codecs. VideoDrive (as do all other tools) uses QuickTime to convert your videos. If the video doesn't play in QuickTime, the conversion will fail. Have you installed Perian?
I noticed VideoDrive released a beta version of 2.3 which includes support for HandBrake. I think this will be a hugh improvement as HandBrake is far more reliable and definitely much faster than QuickTime for conversions.