Hmm, pulling up the equipment associated with your profile, the tuner in one of your clients is returning invalid downstream and SNR readings and both of the two tuners in your host are returning good downstream but invalid SNR readings.
That usually means one (or possibly more than one) of three conditions are happening. 1, the WHDVR network is out of sync, 2, there's a signal problem in the house, or 3, those tuners have gone bad.
The only thing we can recommend is to check all cable connections, then power-cycle all the receivers, starting with the host. If things don't return to normal after that, then we'd have to place a service call.