BSOD in Win'2k3, Vista x86 and x64 by nonpriviledged user

BSOD or hard system hang due to race condition in win32k. sys code that processes UnhookWindowsHookEx. Reproduced when thread calls many times UnhookWindowsHookEx in the same time with switching active windows desktop object SwitchDesktop from desktop where hooks are unhooked and broadcasting...