Follow up your email to the seller with the transaction number of your Paypal payment. That should be enough to push him into accepting that you have both won and paid for the item.
If not there are remedies. Don't panic.
If your PP account is backed only by a bank account, you wrote an "e-cheque" and it has not yet cleared the US and Canadian banking systems. Even if your seller is in Canada, it has to clear both because PP is a US company. This takes a few days and the seller cannot print your shipping label until it does.
If your seller is new, there may be another problem, but don't worry about that now. Let us know if he has fewer than 25 dales, though.
Any member in any country can view and usually order from any of the many national eBays. The nice thing about eBay Canada, besides how polite and cuddly we all are, is that we are used to international buying and selling, which can be a mystery to Americans.