In reply to:
Incorrect spelling, capitalization (why do some people submit a song title like it's a sentence and not an actual title?), and sometimes song titles that are simply wrong. That's what I find from about 25% of the stuff I get from FreeDB. Honestly, I don't remember that much bad information from CDDB when it was still free.
Not to mention duplicate entries. Most all of the CD's i've used FreeDB with have come up in like three different genres in three different entries. It's like people are so anxious to put their version of the CD in there, that they don't care if it's already in there.