This whole iCloud/MobileMe/Apple ID is a mess.
All of my music was bought with one Apple ID and I had a Mobile Me account.
I want one account, so today I decided to just use my Mobile Me address and download my apps again, only a few were purchases anyway.
After removing all iPhone backups, resetting my phone, somehow I still have all the apps and music on my phone from the the non Mobile Me account!
It is driving me ad now!