I had the same problem with the tripp-lite power alert V12.04 software not recognizing the UPS when plugged into a USB port. According to tech support, not all USB ports are compatible with the HID specifications of their USB port. They suggested hooking up the UPS thru a USB hub. I hooked it up to a powered USB 2 hub and the software found the UPS.
Did a lost power test and it works perfectly!