Had an issue with my system this morning that involved me removing my graphics cards. Since then I have issues getting 3+1 surround display working, If I enable activate all displays, then all four monitors will work with no issues.
If I enable surround display, the 3 monitors connected to the sli gfx's will work, how ever it will disable the on board monitor. Windows will still see the monitor there it just wont let me enable it with the other 3 with sli turned on.
This was working perfectly fine till this morning, and I am unable to remember how I was able to get it working again.