To address at least part of the problem, confirm is that the videos are in a format iTunes can accept and play. AVI is not one of them, for instance. See:
Note that there are non-standard formats that still use the .mp4 file extension. iTunes supports only industry-standard MPEG-4 movies, not the offshoots created by some encoders such as Microsoft's.
Why a movie that worked previously is not working now, though, I don't know. Just to confirm, will that movie play in QuickTime Player?
Thanks for the quick reply.
The movie does inded play in the QuickTime player.
It is an .mp4 file.
I just don't get why there is no message of any kind, and the fact I get the exact
same results on Windows 7 as I do on OS/X Lion.
Any why it worked a couple of days ago, I have no idea. As I recall, I used the Drag & Drop method.
As a general rule, is it OK to assume if it plays in QuickTime, it should be able to imported into the iTunes library?
OK, don't ask me why, but this morning, I attempted to add the same movie to iTunes, and this time it worked. Progress bar and everything. As a matter of fact, I managed to import several MP4's.
As you noted, AVIs are not supported, but I'm wondering why there is absolutely no indication of that. When I drag&drop, I get the '+' icon as if all is well, but beyond that get nothing when I drop. Is this normal? I'm suprised that there is not some kind of indication.