Well, not a scam, which would be taking the money and not sending anything.
BUT.
Does the seller ship to Canada? Is the seller enrolled in the Global Shipping Program?
Before we deal with that though.
Don't just email the seller with the link to the payment.
To win the case you must put the Paypal transaction number in the DISPUTE, which will prove to eBay that you have in fact paid, and the seller is the problem.
You are not talking to the seller, you are now facing a 'judge'. Talk only in the Dispute.
While this may or may not get your purchase shipped, it should prevent you getting a Strike as a non-paying bidder. While one of those is not a huge problem, a second would make it difficult to continue bidding on eBay since many, if not most, sellers have automatic Blocks against bids from members with deadbeat Strikes.
Back to why the seller is not claiming your payment.
He may not want to ship internationally. The GSP was by default enrolling many sellers, especially newbies, who were not interested in international shipping.
Is your PP backed with a credit card? If you are backing your PP with a bank account, there can be a delay of up to 10 days while this 'e-cheque' clears the US and Canadian banking systems. This can panic new sellers or those who have never dealt with a foreign buyer before.
Is the seller brand new? He may not realize that Paypal is Holding your cleared payment for up to 21 days against his good service and thinks that Hold means you haven't paid.
None the less, show the Dispute that you have paid. And don't expect to see the purchase. If you get your money refunded that will probably be better than being told that it has been 'lost in the mail' or 'the dog ate it' or 'sorry, it broke when I went to pack it.'