Yes, on top of losing all album art save one (every song shows the same album art) all of my songs show unknown artist. All the songs are there, and like you they all show correctly on pc, but they are all unknown artist on phone stock music player. One other thing, tried a hard reset, did not resolve.
Which again supports my suspicion:
Maybe Froyo enabled/disabled certain ID3v1/2 tags which is why some people are experiencing missing data and some aren't? I'll have to experiment this weekend.
