diff -p -up xserver-xorg-video-psb-0.31.0/libmm/mm_drm.c.assert xserver-xorg-video-psb-0.31.0/libmm/mm_drm.c
--- xserver-xorg-video-psb-0.31.0/libmm/mm_drm.c.assert	2010-04-26 13:40:50.000000000 +0200
+++ xserver-xorg-video-psb-0.31.0/libmm/mm_drm.c	2010-04-26 13:48:28.000000000 +0200

--- xserver-xorg-video-psb-0.31.0/src/psb_crtc.c.randr	2009-05-11 20:37:53.000000000 -0500
+++ xserver-xorg-video-psb-0.31.0/src/psb_crtc.c	2010-11-30 22:50:43.000000000 -0500
@@ -431,7 +431,9 @@
 			if (bPlaneBEnabled)
 			{   
 				//current mode dot clock, HZ
-				DotClockB = output->crtc->mode.Clock * 1000 / WM_DOTCLOCK_DIVISOR;
+                                if( output->crtc ){
+                                      DotClockB = output->crtc->mode.Clock * 1000 / WM_DOTCLOCK_DIVISOR;
+                                }  
 				BPPB = output->scrn->bitsPerPixel;
 			}
 		}
@@ -440,7 +442,9 @@
 		{
 			if (bPlaneAEnabled)
 			{
-				DotClockA = output->crtc->mode.Clock * 1000 / WM_DOTCLOCK_DIVISOR;
+			        if( output->crtc ) {
+				      DotClockA = output->crtc->mode.Clock * 1000 / WM_DOTCLOCK_DIVISOR;
+				}
 				BPPA = output->scrn->bitsPerPixel;
 			}
 		}