Upgraded from 2 Nvidia cards to 3 and not detected in S@H -only two

Hi, I'm looking for some assistance trying to get my third card to work with S@H.
Previously I had two very good functioning Nvidia GTX275's running in non-SLI mode on an Intel Skulltrail motherboard that supports up to 4 x16 PCI-E slots. I have added a third card and it was installed properly in my installation of Server 2008 R2 which is essentially Windows 7 x64. There are no issues in the device manager and I can connect a monitor to the output and it does detect my monitor as being connected.

I have tried to do a repair installation of S@H and there is still no change in the detection of the 3rd card. Additionally I have reset my project and am running the most current version of the application and all of the most current drivers from Nvidia.

Any suggestions would be helpful!
Many thanks!
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I cannot remember where I read it, but there are instances where additional cards have to have a monitor or a dummy load plugged into them to register with the system. Alternately, you might want to look into setting up a 3-way SLI setup. If I understand correctly, CUDA would recognize the SLI setup as a single GPU, but would work all of the cards. I'll try to find some info to back this up.
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I got it to work now - it was like magic after I plugged in another monitor to the system.
Thanks for looking into this.
Todd
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