diff -up ClanLib-1.0.0/Sources/GL/GLX/display_window_opengl.cpp~ ClanLib-1.0.0/Sources/GL/GLX/display_window_opengl.cpp
--- ClanLib-1.0.0/Sources/GL/GLX/display_window_opengl.cpp~	2008-11-13 17:09:02.000000000 +0100
+++ ClanLib-1.0.0/Sources/GL/GLX/display_window_opengl.cpp	2009-09-10 22:58:10.000000000 +0200
@@ -612,6 +612,13 @@ void CL_DisplayWindow_OpenGL::set_resolu
 				XF86VidModeGetViewPort(disp, vi->screen,
 					&old_x, &old_y);
 			}
+			/* Warp the pointer to the upper left corner, this is
+			   necessary as the: XF86VidModeSetViewPort() call
+			   below does not seem to do anything on newer Xorg
+			   servers, instead the viewport appears to be always
+			   centered at the last mouse position */
+			XWarpPointer(disp, None, XDefaultRootWindow(disp),
+				     0, 0, 0, 0, 0, 0);
 			XF86VidModeSwitchToMode(disp, vi->screen,
 				modes[i]);
 		}