Non-dev version is 1.1+ I think. I have 1.2 last I checked.
No idea how to check. Steam should mandate change logs and keep update history separate from the regular news. Still, Steam probably has mine on the latest version, and if his was installed from the retail copy that never had that problem, then it probably isn't the dev version.
I tried some solutions that were posted around, namely toggling VSync and switching to single player mode, neither worked, or I did it wrong.
