I would ignore this little piece of advice
"Buenchico
Sun 05/04/09
19:46
In practice, the Canadian authorities don't know about (and probably don't really care much about) most criminal convictions unless they relate to 'cross-border' offences, such as drug-trafficking, terrorism, etc. However, if anyone in your party is asked about criminal convictions (which is probably extremely unlikely) it would be wise to keep quiet about any they might have."
If anyone has a criminal record Canada know about it. lying to immigration is a criminal offense in itself, so off to jail, or immediate refusal of entry, for the person who lies. Suggesting you lie to immigration is really BAD advice.
Canada/US have co-operated on data sharing of criminal rcords since June 2002 - including biometrics, as do the UK and Canada/US/Australia
This information is even published in the UK Border Agency website, and elsewhere on the net - example
http://www.theregister.co.uk/2009/04/03/ukba_o verseas_fingerprint_exchange/
What you could get away with last year, WILL come back to bite you the next time you try and entry the country.