One thing I notice about AB is that is doe not handle losing focus well. At all.

If you tab out at any time while playing and then return to the game you're almost guaranteed a crash next time you try to launch into a battle. You'll just get the loading screen endlessly and will lose any oil you spent starting that battle. I'm more or less forced to shut the game down if I want to do anything else for any amount of time. That is something of a fatal flaw for a browser game.