iCloud backup and restore: 2 Apple IDs

[msvadi]

I have two Apple IDs. My primary Apple ID is associated with the Canadian iTunes store and the second one is associate with the US store. I had to restore my iPhone from iCloud a couple of times. I always sign in with my Canadian Apple ID, however, when I get to the restore from iCloud step, it asks me for my password for my second (US) Apple ID.

Can, please, somebody explain what's going one? It looks as if my iPhone uses my primary Apple ID for all purposes except for iCloud backup and restore. Actually, I don't even know how my iPhone "knows" about the second Apple ID since I never used it with the phone, only with my Mac.

 

[msvadi]

Ok, found it: http://support.apple.com/kb/TS4036 "I'm asked to enter multiple Apple IDs and passwords during the restore process."

So, if somebody has music on his iPhone purchased from iTunes using several different accounts, and he does not know the password for one of them, he won't be able to restore from iCloud? Even if the phone does not back up music to iCloud?