Of dozens of trips to Canada I was only asked once, that was in Toronto
airport while on a business trip and was pulled aside for further
questioning about the purpose of my visit. I was granted entry under NAFTA
but was asked if I had a DUI or was convicted of a a misdemeanor or felony.
I said no, which was accurate and was allowed to enter, I am not sure if/how
they would check the validity of the response. I think this is a way to
deny entry to people they consider to be marginal and my guess is that it is
selectively enforced. Most of my experience is with the east coast I do
know from experience that they interpret the rules differently at
differently entry points, and it also comes down to the skill and discretion
of the agent.

Rick wrote in message ...
You would appear to be correct, though how they would actually find
out is beyond me.

"INADMISSIBLE CLASSES:

Members of Inadmissible Classes include those who have been convicted
of MINOR OFFENCES (including shoplifting, theft, assault, dangerous
driving, unauthorized possession of a firearm, possession of illegal
substances, etc.), or of INDICTABLE CRIMINAL OFFENCES (including
assault with a deadly weapon, manslaughter, etc.). As well, those who
have been convicted of DRIVING WHILE INTOXICATED (DWI) are considered
Members of an Inadmissible Class. Driving while under the influence of
alcohol is regarded as an extremely serious offence in Canada."

From:
http://www.canadianembassy.org/immigration/inadmissible-en.asp