diff -ur mesa/src/mesa/drivers/dri/r200/r200_context.c mesa/src/mesa/drivers/dri/r200/r200_context.c
--- mesa/src/mesa/drivers/dri/r200/r200_context.c	2007-02-02 12:59:03.000000000 +0000
+++ mesa/src/mesa/drivers/dri/r200/r200_context.c	2007-03-10 08:54:51.000000000 +0000
@@ -673,11 +673,13 @@
 				&newCtx->vbl_seq );
       }
 
+      newCtx->dri.readable = driReadPriv;
+
       if ( newCtx->dri.drawable != driDrawPriv ||
-           newCtx->dri.readable != driReadPriv ) {
+           newCtx->lastStamp != driDrawPriv->lastStamp ) {
 	 newCtx->dri.drawable = driDrawPriv;
-	 newCtx->dri.readable = driReadPriv;
 
+	 r200SetCliprects(newCtx, GL_BACK_LEFT);
 	 r200UpdateWindow( newCtx->glCtx );
 	 r200UpdateViewportOffset( newCtx->glCtx );
       }
diff -ur mesa/src/mesa/drivers/dri/r200/r200_lock.c mesa/src/mesa/drivers/dri/r200/r200_lock.c
--- mesa/src/mesa/drivers/dri/r200/r200_lock.c	2006-12-05 23:42:18.000000000 +0000
+++ mesa/src/mesa/drivers/dri/r200/r200_lock.c	2007-03-10 08:54:38.000000000 +0000
@@ -98,7 +98,6 @@
          r200SetCliprects( rmesa, GL_FRONT_LEFT );
       r200UpdateViewportOffset( rmesa->glCtx );
       driUpdateFramebufferSize(rmesa->glCtx, drawable);
-      rmesa->lastStamp = drawable->lastStamp;
    }
 
    R200_STATECHANGE( rmesa, ctx );
diff -ur mesa/src/mesa/drivers/dri/r200/r200_state.c mesa/src/mesa/drivers/dri/r200/r200_state.c
--- mesa/src/mesa/drivers/dri/r200/r200_state.c	2007-02-03 06:58:27.000000000 +0000
+++ mesa/src/mesa/drivers/dri/r200/r200_state.c	2007-03-10 08:54:38.000000000 +0000
@@ -1889,6 +1889,8 @@
 
    if (rmesa->state.scissor.enabled)
       r200RecalcScissorRects( rmesa );
+
+   rmesa->lastStamp = drawable->lastStamp;
 }
 
 
diff -ur mesa/src/mesa/drivers/dri/radeon/radeon_context.c mesa/src/mesa/drivers/dri/radeon/radeon_context.c
--- mesa/src/mesa/drivers/dri/radeon/radeon_context.c	2007-02-02 12:59:03.000000000 +0000
+++ mesa/src/mesa/drivers/dri/radeon/radeon_context.c	2007-03-10 09:07:21.000000000 +0000
@@ -594,12 +594,14 @@
 	 driDrawableInitVBlank( driDrawPriv, newCtx->vblank_flags,
 				&newCtx->vbl_seq );
       }
-      
-      if ( (newCtx->dri.drawable != driDrawPriv)
-	   || (newCtx->dri.readable != driReadPriv) ) {
+
+      newCtx->dri.readable = driReadPriv;
+
+      if ( (newCtx->dri.drawable != driDrawPriv) ||
+           newCtx->lastStamp != driDrawPriv->lastStamp ) {
 	 newCtx->dri.drawable = driDrawPriv;
-	 newCtx->dri.readable = driReadPriv;
 
+	 radeonSetCliprects(newCtx);
 	 radeonUpdateWindow( newCtx->glCtx );
 	 radeonUpdateViewportOffset( newCtx->glCtx );
       }
diff -ur mesa/src/mesa/drivers/dri/radeon/radeon_lock.c mesa/src/mesa/drivers/dri/radeon/radeon_lock.c
--- mesa/src/mesa/drivers/dri/radeon/radeon_lock.c	2006-12-05 23:42:18.000000000 +0000
+++ mesa/src/mesa/drivers/dri/radeon/radeon_lock.c	2007-03-10 09:00:47.000000000 +0000
@@ -96,7 +96,6 @@
       radeonSetCliprects( rmesa );
       radeonUpdateViewportOffset( rmesa->glCtx );
       driUpdateFramebufferSize(rmesa->glCtx, drawable);
-      rmesa->lastStamp = drawable->lastStamp;
    }
 
    RADEON_STATECHANGE( rmesa, ctx );
diff -ur mesa/src/mesa/drivers/dri/radeon/radeon_state.c mesa/src/mesa/drivers/dri/radeon/radeon_state.c
--- mesa/src/mesa/drivers/dri/radeon/radeon_state.c	2007-02-02 12:59:03.000000000 +0000
+++ mesa/src/mesa/drivers/dri/radeon/radeon_state.c	2007-03-10 08:58:29.000000000 +0000
@@ -1675,6 +1675,8 @@
 
    if (rmesa->state.scissor.enabled)
       radeonRecalcScissorRects( rmesa );
+
+   rmesa->lastStamp = drawable->lastStamp;
 }