Welcome to the forum
I'm converting from MusicMatch 10 to MJ12 (running 12.0.25).
A good choice. MC12 and MJ12 have about the best available support for proprietary MusicMatch tags. Most of them are available, but you may need to enable them manually. If you are missing a specific tag you may want to do a forum search for MusicMatch (most of the posts are in the MC12 and MC11 boards so remember to include them in the search).
After importing my 35,000 file library (into MJ12), I have 68 tracks in the "Unassigned" artist, but MusicMatch finds the tags of these .mp3 files just fine.
Are you saying that only the Artist tag is missing? The Artist tag is standard and should show up automatically. Probably the tags are more or less corrupted somehow.
It seems odd because I know all tracks in my library are tagged, but it's only these certain few tracks. Is there a place I can upload one of them?
Luckily only 68 files have the problem. Possibly you could use the "Fill Properties From Filename" tool for adding the missing info from the filename or path.
However it would be interesting to see what causes the problem. You could use the
www.rapidshare.com service for providing a sample. Put the MP3 file in a zip package and give the zip file an anonymous name before uploading. Post the link here.