I just installed an MGE ellipse 500 UPS with USB which, in theory, should be able to shut down and then start up any USB mac. However, the MGE UPS control panel (to control these functions) won't open because:

"PowerMgrLib can't be opened-Can't find "UpdatePowerSource
You may need to reinstall PowerMgrLib"

So, it looks like PowerMgrLib is integrated into the Finder (?), and I clean installed last night, but same problem.