Did you set your buyer requirements? If you don't want to ship outside Canada, you have to set your buyer requirements.
To block buyers whose primary shipping address is in a country you don't ship to:
Click the Account tab, and then click Site Preferences link on the left.
In the Selling Preferences section, scroll to Shipping preferences, and then click the Show link.
Click Exclude shipping locations from your listings.
Select one or more continents to exclude all countries on those continents. Or select Show all countries and check the specific countries you don't want to ship to.
All excluded countries you selected will appear on the lower section of the page.
You can select to apply these exclusions to all current live listings on a global level.
Click the Apply button to save your requirements.
http://pages.ebay.ca/help/sell/buyer-requirements.html#specifying
Also, on the advanced listing form, (after International Shipping) there's an area to set your Excluded Locations list.