This is a compatibility issue that we are seeing with the UF series by CME (UF 50, 60, & 70). Check to see if you have installed the Vista service pack 1. This service pack is currently causing audio devices to not work on the Vista platform. You can try removing the service pack to see if that fixes the problem.
Currently the CME website only qualifies their products to work with Windows XP Sp2.
Check the CME Website for more information.