I noticed on Windows 8 that there is a StrokesPlus icon on the taskbar (like a regular program). Also, if the Keep Gesture Window on Top setting is checked and you kill Explorer.exe and restart the shell, Windows 7 puts a StrokesPlus taskbar button there.
It appears adding WS_EX_TOOLWINDOW fixed the issue in Windows 7, so I'm hoping MS realizes the issue with Win8 CP and corrects. Changing this to DEFERRED for now.
Tried your program on Release Preview. Looks like you fixed it and StorkeIt doesn't. Great Job! Now I have a good reason to kick my rear and start migrating. Thanks!