I was in Canadian Tire a while ago and bought a package of five Mastercraft sanding belts for my Craftsman sander. The initial two were fine. However, I went to use them recently, and all three broke one after the other at the glue seam after only a minute or so on the sander. I've never had this happen before. They weren't cheap either. I looked more closely at the package: "Imported for..."
I frequently rail on this blog against cheap products, which are usually made in China. Of all people, then, I should know better to look at the source of items before buying them. Someone up the food chain obviously decided they could save a few pennies per belt by using lower quality adhesive. I've since bought some new belts at Lowes, made the U.S.A. No problem with them.
I've marked the Crap Tire package "Junk" and stapled it above where I store my extra belts, just to remind me to never buy from this source again. "Superior line of my products" my ass.