yeah ive gone a bunch  of times too, and i have a minor criminal record.   
never had any problems going in or getting back.    
 but according to that article, people are starting to get some guff at the border.    
""People say, 'I've been going to Canada for 20 years and never had a  problem,' '' Lesperance says. "It's classic. I say, 'Well, you've been getting  away with it for 20 years.' ''"   
hell that one guy got busted with pot in 1975. now he owns a 3 million dollar house in lake tahoe, but they still got him    
"The Canadian Border Services Agency says its statistics don't show an  increase in the number of travelers turned back. But Cannon says that's because  the "data mining'' has just begun to pick up momentum"