I'm not much help on this one Steve, mostly posting to lurk this thread..
Windows or a Mac machine? I'd check Device Manager for it first if Windows.
Here's the reason for my lurk-
Multichannel LPCM output. I've been meaning for years to pick up a laptop with an HDMI port + an HDMI input hometheater receiver for simple and direct 1-cable connected mulitchannel LPCM playback from the computer. It would eliminate the need for a multichannel capable USB DAC, the extra DAC>analog>ADC conversion, and the mess of RCA interconnects. Any insight into that is welcome, but please adress Steve's questions first! I'm just riding his coat-tails here.