I am in the Dallas area and is having the same problem. I think it started sometime over the last weekend. My TR40 (F103) lost KERA digital 13.1. After a rescan, it found 14.1, 14.2 and 14.3, but the TR40 was not able to lock on to the very weak signals.
This problem is not limited to the TR40, I have a CM-7000 also, and it shows the same problem.
My other CECBs, a RCA DTA800B and a Zenith DTT900 pick up 13.1 just fine. So is my HDTV, which picks up both the digit and analog channels for KERA with no problem.
So much for the sensitibility for the pal and CM.