I am having the same issue. Have you perhaps found a solution?
USB mode works flawlessly. However iCue cannot see the dongle (under settings, the "Dongle Firmware v." line shows a "?").
I cannot update the k57's firmware as iCue says: "Plug in the USB wireless receiver to start the update".
I've tried plugging the receiver into other ports to no avail. Im running the latest iCue software, and I've updated Windows.
Is there a particular driver that i should try to remove and reinstall in device manager?