Hello -
Having the same issue on Win7 with all USB 3.0 ports. I tried the zadig tool with no improvement. If it helps any, flirc also shows up under Devices and Printers and I see it in the Device Manager.
This isn't a huge deal for me, personally. I was planning to use this on a machine with USB 2.0 ports, but was hoping to experiment with the programming on a (more convenient to use) laptop before messing with my Media Center configuration.
Just thought it might be useful to report back and to offer any sort of help I can.
Thanks!