Question : Problem: Horizontal spanning with ATI graphics cards?

I have 2 radeon 4870 cards running in crossfire and 2 monitors.  A dell 30" dell monitor running in 2560x1600 and a 20" dell monitor running in 1200x1600 (turned on its side), i want to do horizontal spanning like on nvidia cards where it will let you span a single resolution across 2 monitors but i can't find a ready answer as to whether this is capable on ATI cards.  it essentially would show a single resolution of 3760x1600.  I am running the Catalyst Control Center and drivers version 9.1 and have tried to find an answer from multiple sources.  Any ideas?  I've heard of ultramon but i would perfer to do it with a native solution if possible since i don't know if ultramon means that the spanning would work in open, full screen games.

Answer : Problem: Horizontal spanning with ATI graphics cards?

Got a response from AMD/ATI finally.  This apparently has to do with Vista only with its new display management layer.
http://support.ati.com/ics/support/default.asp?deptID=894&task=knowledge&questionID=26771