I agree with FRANKDAMP....Altho many think Canada is simply a suburb of the United States, Canada IS a different Country and does many things differently.
I think the CANADA coversion just might be different from the US conversion. Have you turned your TV back on since returning FROM Canada? (Last time I was in Canada, even the cell phones were different...I was advised to contact my cell phone carrier, pay a nominal fee...then I could use my American cell phone in Canada....or...pay as much as 7 bucks a minite.)
Suggestion: Unplug the converter. Let it sit for maybe 10-20 seconds, plug back in, reboot and then scan for channels.