Occasionally, mouse-clicks aren't registering in the skill check roll. The die roll requirement sits there awaiting my click, but doesn't accept the input. I can see the little finger curl when I click so the UI apparently receives signal, it just isn't reaching where it needs to. Specific instance was a tough charisma check after finding a battered ancient helmet in the blighted village that startled my secretive cleric and gave her a brief glowy on the back of her left hand, immediately following a fairly intense skirmish with goblins.
And speaking of that goblin skirmish, goblins on the roof seem to have no problem firing arrows and casting spells through the roof and through walls but return fire is inevitably obstructed.