I've noticed a trend that is becoming kind of annoying. For some reason it always happens at either Shoppers Drug Mart or London Drugs.
Whenever I have my own bag, it seems that the cashier 75% of the time does not put my groceries in it. This of course never happens if I don't have one. Maybe I'm old school, but unless a store is specifically a bag your own place, cashiers put your items in a bag.