Index: macroblock.c
===================================================================
--- macroblock.c	(revision 531)
+++ macroblock.c	(working copy)
@@ -870,7 +870,7 @@
     int i, j;
     for( i=0; i<2; i++ )
     {
-        int i_refs = i ? 1 + h->param.b_bframe_pyramid : h->param.i_frame_reference;
+        int i_refs = (i ? 1 : h->param.i_frame_reference) + h->param.b_bframe_pyramid;
         for( j=0; j < i_refs; j++ )
             x264_free( h->mb.mvr[i][j] );
     }