diff --git a/layout/generic/nsBlockFrame.cpp b/layout/generic/nsBlockFrame.cpp
index 36177d53e80a..3b780d01c861 100644
--- a/layout/generic/nsBlockFrame.cpp
+++ b/layout/generic/nsBlockFrame.cpp
@@ -5868,7 +5868,11 @@ nsBlockFrame::ReflowDirtyChild(nsIPresShell* aPresShell, nsIFrame* aChild)
     }
 #endif
   }
+#if 0
+  // XXXwaterson Temporarily disable dirty reflow coalescing (which is sort of
+  // silly, anyway, given the reflow tree) until we can figure out bug 143959.
   else {
+    nsIBox *
     if (!(mState & NS_FRAME_IS_DIRTY)) {      
       // Mark yourself as dirty
       mState |= NS_FRAME_IS_DIRTY;
@@ -5888,6 +5892,7 @@ nsBlockFrame::ReflowDirtyChild(nsIPresShell* aPresShell, nsIFrame* aChild)
       mParent->ReflowDirtyChild(aPresShell, this);
     }
   }
+#endif
 
 #ifdef DEBUG
   if (gNoisyReflow) {
diff --git a/layout/html/base/src/nsBlockFrame.cpp b/layout/html/base/src/nsBlockFrame.cpp
index 36177d53e80a..3b780d01c861 100644
--- a/layout/html/base/src/nsBlockFrame.cpp
+++ b/layout/html/base/src/nsBlockFrame.cpp
@@ -5868,7 +5868,11 @@ nsBlockFrame::ReflowDirtyChild(nsIPresShell* aPresShell, nsIFrame* aChild)
     }
 #endif
   }
+#if 0
+  // XXXwaterson Temporarily disable dirty reflow coalescing (which is sort of
+  // silly, anyway, given the reflow tree) until we can figure out bug 143959.
   else {
+    nsIBox *
     if (!(mState & NS_FRAME_IS_DIRTY)) {      
       // Mark yourself as dirty
       mState |= NS_FRAME_IS_DIRTY;
@@ -5888,6 +5892,7 @@ nsBlockFrame::ReflowDirtyChild(nsIPresShell* aPresShell, nsIFrame* aChild)
       mParent->ReflowDirtyChild(aPresShell, this);
     }
   }
+#endif
 
 #ifdef DEBUG
   if (gNoisyReflow) {