I just got my 721 installed today, and, as a receiver/PVR, it seems to work great. No problems getting the guide, no problems with time zone and future recordings, etc. However, I discovered within a couple of hours that whenever someone called my home number, the phone would ring once, then they would simply hear silence. After some experimentation, I discovered that it only happened if the 721's modem port was connected. I tried connecting a phone instead of the 721, and it worked perfectly. I tried unplugging it, and it worked fine until the boot process completed, then it started screwing up again. I talked to adv. tech support, and they didn't even try troubleshooting; they just said they'd replace it (with a new one, as it's brand spanking new - had it for 6 hours). Has anyone else experienced anything like this? Any other suggestions? I'd love to get it figured out then just send back the RMA'd one they send me so I can start recording shows instead of waiting a week since I'll lose it anyway.