can't authorize song purchased with old itunes account??

I upgraded to Snow Leopard and loaded my itunes library and playlists successfully. BUT there is a problem. When I try to play songs which I downloaded with an older itunes account it says "This computer is not authorized to play 'example song.' Would you like to authorize it?"

The problem is that I don't have the old email account which corresponds with that respective itunes account. I can't answer the sercurity questions either...