Hi georgesimeonoff and eyeball1,
It seems that you are having some issues in order to enter the Canadian postal codes when setting up your Slingbox for Internet Viewing.
There are two details that you must pay attention: first, select Canada in the Country Selector page (just before accessing to www.slingbox.com). This selection will allow you to get all the information which is available for Canadian customers.
The second step is to select Canada on the drop-down menu on the Setup Assistant's first screen (the page where you type in the password you will use for your Slingbox). You should be able to click on the drop down menu and select Canada as the Slingbox country.
One you follow these steps, you should be able to enter the Canadian postal codes.
Hope this helps!