Hidden Layered Window?

Hello. I'm a fairly new WindowBlinds user and I've noticed an odd (possible) bug with WB. Sometimes when I shutdown my computer I will get an End Task window that says "Hidden Layered Window" is unresponsive and needs to shutdown. I googled this, and while most people seem to think its spyware, I found one result for the MS window drawing API. I have freshly installed xp and I'm familiar with my process list and steering clear of spyware/viruses, so my guess is this is a feature that WB uses to draw some of its fancy effects. Basically I just want to confirm/disprove my theory that this is or could be, Windowblinds. I can try to post a screen shot and/or some system information if that would help Thanks