Switchport Mapper Deletes Monitored Devices

I tried to use SwitchPort Mapper. It didn't list any switches, even though I had many added. I'm guessing it only thinks devices in the "Switches" category are switches. How do you use SwitchPort mapper on switches that you define in a custom infrastructure? It should allow you to choose ANY device you add.

Since it didnt list any devices, I just tried adding one (it was already added under a custom view), but it said the device did not exist. Then I went back to my view and lo'and'behold, the device was GONE. I can't re-add it either, because it says "Some stray entries found for this device". I can't delete it because it doesn't exist in the GUI. This JUST happened to me doing something else the order day and I JUST got done re-entering all our devices, and it happens again.