You need to use a different aticonfig command after installation for Multiview. Matthew (mtippett) posted about it maybe a month ago, let me see if I can find it...
OK, I think this is the post I was looking for :
http://www.phoronix.com/forums/showp...6&postcount=23
... and another post which includes enabling Xinerama...
http://www.phoronix.com/forums/showp...7&postcount=26


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