TV Guide ends Tuesday 5pm. "To Be Announced" appears.

This is the 3rd time i've had this happen.  The fix is easy. I unplug the unit for 2 minutes. Then wait 10-60 minutes for the guide to repopulate.  Is there any pattern to this occurrence?  I have a Cisco 9865 (Record 6) in Phoenix.  Is it happening to 1 unit out of 100?  1 out of 10,000?  Is it happening more in some cities than others?  It is a very minor problem. I don't want to have a technician come out. Has anyone learned anything more about why it is happening?  (in a previous thread a Cox moderator said she might look at a software update).

Before the problem hits, i can look in my "Scheduled" list and see more than 7 days worth of shows to be recorded. After the problem hits, those disappear from the Scheduled list and "To Be Announced" appears in every space in the Guide.  The problem has always happened on a Sunday. It means i have to be vigilant about looking at my Scheduled list because the shows won't record if the Guide is empty.

In response to an earlier question, one person said that my box fails to send a request for the newest Guide information. That is why "To Be Announced" appears.  That made sense.  But that is not what is happening.  I am having the information disappear after it is already at my box. One day i have Guide listings for over a week in advance.  When the problem hits, i have Guide information for only 1-2 days. All Scheduled shows after the 1-2 days is wiped out.