I have never had a problem with caller ID on my 721. You might want to check your outside ground (on your switch or ground block). I know somone that had a caller ID problem and after he corrected his (lack of) grounding it went away.
The switch is grounded. The problem is I don't have any other caller ID display unit, and I've been having issues with getting it set up properly by Qwest. I called them the other day and they said they had it installed on our second line, which has been disconnected, so they put it on the main line but said it would take a day or so to start working.
Okay, I got a caller ID phone and I confirmed that the caller ID is working on the line. So any ideas as to why it's not working on the 721? I set it to display caller ID info. Is thre anything else I need to do to turn it on?
Seriously , some times mine works and sometimes it doesn't. I usually go into the prefrence menu and reinstall my caller id . I also reboot the 721 with a power button reboot. If all else fails I do the smartcard reboot. This usually fixes it on my unit.
(knocking on wood) The caller ID has always worked on my 721. I didn't do anything special other than turn it on in the menu upon initial setup. The CID function has successfully survived all software updates too. The incoming satellite cable shield is and has always been grounded to an 8' copper grounding rod outside the house. BTW, anyone know how large the history file can grow? I was going through the caller history a few weeks ago and was able to go back through more than 6 months of incoming calls before giving up. I suspect it goes all the way back to last January when I first installed the receiver.