"Welcome back" popup doesn't redraw when computer is unlocked.

When I leave my computer for any length of time I lock it to avoid becoming the victim of some hilarious jape or other, but when I come back and unlock it, the RescueTime "Welcome Back" popup window is a completely black rectangle with only a "meeting" button and I can't seem to make it redraw, so any time I lock my machine I have to register as having been in a meeting, no matter what I was actually doing.