I have two Cisco DVRs and 3 Cisco non-DVR STBs. About two weeks ago, the Mute button stopped working on one DVR (everything else is OK), and Caller ID stopped working on the other (it is enabled). Not sure the problems started at exactly the same time, but close. I've re-booted both with no luck.
I have sent you a private message to get your account information so we can help troubleshoot the issues with your DVR's.