I've only experienced this once and that was with a Miyata 1000 that I bought a couple months back. I'm pretty sure that nothing had been done to the Miyata since new as it still had the original tires and the original sponge on the bars, etc. The crank was tight on both sides, but a couple whacks (and who wouldn't want to whack a crank?) with a light hammer on the old Park crank tool and they were free, free, free at last.