Album artwork wrong on iPhone

Ok, so I know this may not seem like a huge issue to some people but for anal people like me it is. So I have just downloaded iTunes 8 and upgraded to software 2.1. First problem I encountered was all of my music on my iPhone not transferring over into iTunes 8 so I had to upload about 2-3 albums back onto iTunes. But more importantly...I got everything back up and running and I synced all music onto my phone and as I started playing my music I seen that some of the album artwork did not match the song I was playing. Not all songs are like this, but some of them are. I would be listening to "Shaking" by Sugarcult and the artwork to the Soundtrack of Sex and the City would come up and its really starting to **** me off. Anyone having the same problem? Anyone know how to fix it? Oh! and also, When I'm on iTunes the correct album artwork would show up. But alas my phone has yet to fix the problem.