...a "compilation" setting problem.

As I always do, I imported a CD, selected all the tracks, Got Info, found an image of the art on the web, copied, pasted into the small art window in iTunes (and the art was visible in the little art win, closed the window dow)...
...and no art in the left column.

Did it again, from a different source picture. Nothing. And then copied from the browser into Word, PAste special to be sure I was getting an image. Copied that. Still nothing. If I open the Get Info pane of each song, the art is there. If I select all, it is blank.

Just did the same for a different album-no problem at all.

Hey...why is album name "unknown"? They all have the same name!

Uh-"compilations" is YES. Change to NO.
Problem solved.

--> I guess iTunes freaks out if you have a compilation where the artists are all the same?

This album was "Wicked: Original Broadway Cast" and I had changed all the artist names to just "Wicked" instead of Kristin Chenoweth etc. Apparently that freaked things out...though now I can change compilations YES or NO and it's fine.

Ah, software. Can't live without it, can't commit mass murder to the careless lazy developers...

Hope this helps someone.