Global hooks getting lost on Windows 7

Some time ago a customer of mine reported the following issue with SetWindowsHookEx API:Their application had global hooks to monitor for both keyboard and mouse input. On Windows 7, and under high CPU usage, those hooks were getting lost. They tried several things to solve the issue, without success: adjust registry setting "Control Panel\Desktop\LowLevelKeyboardProc" to 10000 (10sec), restart