Thx for your reply.
I have enabled both the nonexlucisve and foreground flag:
// changed lines in ExampleFrameListener.h
...
#if defined OIS_WIN32_PLATFORM
win->getCustomAttribute("HWND", &windowHnd);
pl.insert(std::make_pair(std::string("w32_mouse"), std::string("DISCL_NONEXCLUSIVE")));
pl.insert(std::make_pair(std::string("w32_mouse"), std::string("DISCL_FOREGROUND")));
#elif defined OIS_LINUX_PLATFORM
...
All code that connects with OIS is 100% copied from your OIS Ogre example, with only those two startup lines added. The files copied are ExampleApplication.h / GuiFrameListener.h, plus the ExampleFrameListener class from gui.cpp.
I am pretty much helpless with this problem, because i really didn't change anything in those example classes :?
I am using buffered mouse input, btw. does that make a difference?