Best news ever: i found a copy of the v6.25 MSI. I installed it and my EverNote world is back in order. Even better, I clicked on Help > Check for Updates (since i now have a fallback plan) and got this:
Maybe they've pulled this horrific v10 update? And by the way, what happened to v7, v8, and v9? Were they equally horrific and got pulled before the community revolted?