Its being 5 days since last March the 3rd when you say it started happening and I do not find other people having the same issue on several canadian forums. I checked zinwell website and there is a way to update the firmware using the RS-232 COM port but could not find a firmware update at all for your model.

You also mentioned that to "fix" the problem you have to power down the ATSC unit but then you loose the channels so you have to scan them in again. Was that happening before? , Is it normal for your ATSC tuner to loose its memory if you power down completly? I would imagine it would have some sort of memory to keep that info in case of power loss. At least my tuners do keep the info.

Back in late 2006 when the OMNI's went online there was an issue with those 3 stations (CFTO included) related to all of them using the same value (default by factory to 1) on their TSID instead of the value assigned by CRTC/FCC or maybe Industry Canada. Therefore lots of tuners (mostly Samsung made I think) could not map those stations accordingly resulting in only 1 station being mapped at a time. I do not think now the problem is related to the broadcasters but rather your own equipment since nooneelse seems to complain about it.

Hopefully another user with the same ATSC tuner model can chime in and help you further.