I did a search on the topic of issues with the R15 and caller ID and the posts I called up all dated back to 2007-8.
Last Summer I had U-verse internet and phone service installed. For about 6 months the caller ID worked fine and then earlier this year it stopped working. I noticed that suddenly, two days ago it started working again.
Why would the Caller ID stop working for a period of time and without any action on my part start working again? I can't blame it on a reboot while I was at work, as I have had cause to reboot the unit other times and it has had no impact on caller Id. Is this one of the mysteries of the world like bigfoot or the Bermuda Triangle?