diff --git a/layout/generic/nsColumnSetFrame.cpp b/layout/generic/nsColumnSetFrame.cpp
index 3e74faf359d..e808bce9b74 100644
--- a/layout/generic/nsColumnSetFrame.cpp
+++ b/layout/generic/nsColumnSetFrame.cpp
@@ -432,7 +432,8 @@ nsColumnSetFrame::ReflowChildren(nsHTMLReflowMetrics&     aDesiredSize,
       }
 
       nsHTMLReflowState kidReflowState(GetPresContext(), aReflowState, child,
-                                       availSize, tmpReason);
+                                       availSize, availSize.width,
+                                       aReflowState.mComputedHeight, tmpReason);
                                        
 #ifdef DEBUG_roc
       printf("*** Reflowing child #%d %p: reason = %d, availHeight=%d\n",
diff --git a/layout/style/ua.css b/layout/style/ua.css
index ad1d4f8d115..dae1f176d45 100644
--- a/layout/style/ua.css
+++ b/layout/style/ua.css
@@ -153,6 +153,11 @@
   /* the column boxes inside a column-flowed block */
   /* make unicode-bidi inherit, otherwise it has no effect on column boxes */
   unicode-bidi: inherit;
+  /* inherit the outer frame's display, otherwise we turn into an inline */
+  display: inherit !important;
+  /* Carry through our parent's height so that %-height children get
+  their heights set */
+  height: 100%;
 }
 
 *|*::-moz-page, *|*::-moz-page-sequence {