Can any one solve the problem of Nvidia SLI for Multi-Monitoring?

As you know a group of SLI can not support mare than 2 screen.We had a high-end system which contain :
CPU : Intel QX9650
MB : XFX 780i (SLI Support)
VGA : Nvidia 280GTX (3*way SLI)
PSU : 1230 Watt Green (the people in Iran know the brand of green.For the aliens it is the same Seventeen Brand )
Ram : Gskill 2*2 GB
we decided to go 3 screen and multi-monitoring.Some of people said that the latest version of Nvidia driver 180.43 Beta would do that.Some others told us some ways which they called Hack-multi-monitoring(2 monitor attach to 2-way SLI and third have to go to the other VGA,then you disable SLI mode and Disable the third VGA in Display setting and restart and Enable SLI mode )
Guess what ?!!! None of them work. At Last we had to buy a device which call Matrox Triple-Head2GO.In its official website,it said this product support Vista 64.But it wont. At least we access 3-screen.and play Grid and Crysis in 3840x1280.
Know my problem and question is that: Why Nvidia cards would not support multi-monitoring?Do you have any way to go 3-screen?
You can see our review(In Farsi) and pictures and captured films(click on last 3 picture) in this Link : http://www.lioncomputer.ir/index.p [...] ews&&id=85