And, if you don't already, remove the blade after each shave. Dry the blade, and keep it out of the razor somewhere safe and dry. Clean the razor between shaves too, to prevent soap scum build up. I have a piece of cheap magnetic card that I store blades on, with numbers showing how many shaves they had. It helps keep track of the blades, stores them neatly without fear of damage to blade or fingers, and acts as an impetus to clean the razor properly once the blade is out.Problem solved! @Kix for the win. I let the razor soak overnight, scrubbed it with soap and a toothbrush, and then tried again with a fresh Shark blade. (No stub above, @Ron R and @Deano, just a camera that wouldn't focus.) Things were back to normal. There must've just been enough buildup to keep the blade from getting to my skin. I'll try with canned cream again in a bit and come back for one more update. Thanks for the help, everybody.