Actually, the agreement can stand up in court even without notarization. All the notarization is for is to verify that the person signing the document is in fact the person signing the document.
If you sign it and the other person signs it, and it's got all the other essential terms you have to have in it to make it a binding agreement, it doesn't necessarily need to be notarized.
My only suggestion is this: If it's not notarized, have a neutral party present to "witness" the signing by the other party. If you have any suspicion that the other person would deny that it's their signature on the document, have it notarized and/or witnessed by someone not a party to the contract.
But then again, you're in Canada and I don't know Canada law. Hope this was helpful.