Occasionally a 'Running' indicator, a little white triangle is what I have set it as, appears at the edge of my desktop but without the Dock. I have the Dock set to hide unless I mouse over to that edge of the screen. If I see the 'running' indicator showing all by itself (just the little white triangle, nothing else) and then mouse over the edge of the screen so that the Dock appears, the 'running' indicator just disappears. But it comes back again later. And it always seems to be in the same place (right at the edge of the Desktop, about 1/3 of the way along, from the left, of the beginning of the Dock - though that's just an estimate since I can't see where the beginning is as the Dock is set to be hidden).
Is this a bug?
I run Windowblinds as well, in case that makes a difference.