What about this:
http://www.cic.gc.ca/english/resources/tools/temp/visa/validity/expiry.asp
As per R190(3)(f), foreign nationals who are normally required to have TRVs to enter Canada are exempt from that requirement when they seek to re-enter, if, since leaving Canada after being authorized to enter as a temporary resident, they have only visited St. Pierre and Miquelon or the U.S. (including the Territories and Possessions of the U.S., but not including cruises that enter international waters) and:
are returning within the initial period authorized by an officer; or
are in possession of a valid VR, WP, SP or a TRP (authorizing re-entry) and are returning within the initial period authorized by an officer.
I've traveled to the States a few times with a WP and not a valid visa. They never even treat it like it's weird, they just let me back in without questions. Same thing with a study permit. I'm asking because now I have a Visitor Record, which according to the girl at the call centre works just like a WP, and I am going to travel to the States tomorrow. Should I be freaking out? I need to travel, and I'm not going to cancel my trip. I have my Sponsorship Approval with me and my marriage certificate. Also a letter from my husband that he wrote when applying for the visitor extension (saying he's going to support me etc). Will I void the visitor record by travelling to the states? This can't be!