Could you give details about what is slow and how long the shutdown code was active in your worst case?

I did use some tools to investigate Xolox, e.g. MSVC Spy++ or TaskInfo2000 and didn't mention any hidden window or task after shutting down Xolox at all. This is what I mean with the TCP shutdown-code (of XoloX) is usually quicker than humans recognize. When you mention any short time persistant window, please give us name and class so we can further investigate.

Moak