layered hidden window?

Hi all, whenever I shut down my computer just before windows signs off I get a pop up window. The window only lasts a second so I haven't been able to read it in it's entirety but from what I can make out here's what is says.....ending program, pleases wait....and then something about a layered hidden window. I run pest patrol, adaware, and spybot as spyware cleaners, and zone alarm for firewall and virus protection. All scans come up clean so I'm hoping that whatever this is it isn't malicous. My question is, is there some way to find out what this layered hidden window is? It won't stay on long enough for me to read it and it pops up every time I shut my computer down. Thanks for the help, Brian