fixed re-entrant calls to X bug.

platform/CXWindowsScreen.cpp

@@ -387,7 +387,10 @@ CXWindowsScreen::processEvent(XEvent* xevent)
 	}
 
 	// let screen saver have a go
+	{
+		CLock lock(&m_mutex);
 		m_screenSaver->processEvent(xevent);
+	}
 
 	return false;
 }

platform/CXWindowsScreenSaver.h

@@ -16,7 +16,7 @@ class CXWindowsScreenSaver : public IScreenSaver {
 public:
 	// note -- the caller must ensure that Display* passed to c'tor isn't
 	// being used in another call to Xlib when calling any method on this
-	// object (including during the c'tor and d'tor) except processEvent().
+	// object (including during the c'tor and d'tor).
 	CXWindowsScreenSaver(CXWindowsScreen*, Display*);
 	virtual ~CXWindowsScreenSaver();