What is the solution for this Silicon Dust? I have the exact same issue, and it started a few weeks ago (more than enough time for you to resolve this, and let us know).
When I open WMC for the first time, I get the same error "Unable to view channel. No available tuner is able to tune to the requested channel. If you are using a set-top box, make sure the IR control cable is connected and try again."
THe only way I know to resolve it, is to reboot the HD HomeRun Prime. This is not a long term solution, so please let us know how to resolve this.