I don't know if this is a problem with the tags in my files or the way they're being read, but practically all my MP3s display with 0 track length in the playlist and also when I right-click and edit songs the length is 0.
If it's a problem with the tags, is there an easy way to update my MP3s with the correct file length using some tool?
When cue support was introduced I had to change track length from seconds to milliseconds and this is why you have that problem. If you rescan the library the problem will be solved.