Songs I own played by different artist on iPhone app

[Blutch313]

Hello, this is my first post as a Spotify newbie.

Actually, more a probie as I haven't made up my mind yet which service to use. I've been using itunes since it first came out and recently did some GMP as well. Growing frustrated with both so I'd thought I'd give Spotify a try. Currently on Premium.

Here's my issue, and it probably has been discussed elsewhere, I just can't find it: I have a collection of songs on my hard drive that I ripped from CDs or purchased via iTunes. I copied all these songs from my "Local" to the "Your Songs" folder. However, when I shuffle play the songs on my phone using wifi, some of the songs appears to be performed by a different artist. For example: The Beatles vs The Beatles Recovered! Very irritatintg!

Another issue I have: songs from a Greatest Hits compilation shows up under the original album in the phone app.

Any suggestions?

Thanks!