Index: libhb/decavcodec.c
===================================================================
--- libhb/decavcodec.c	(revision 1611)
+++ libhb/decavcodec.c	(working copy)
@@ -691,7 +691,19 @@
             case CODEC_ID_H264:
             case CODEC_ID_VC1:
                 break;
-
+            
+            // We'll also believe timestamps for mpeg-4 part 2, but only in MP4
+            // files, since then we don't have to worry about VFW packed b-frames.
+            case CODEC_ID_MPEG4:
+                if( pv->job != NULL )
+                {
+                    if( strcmp( pv->job->title->container_name, "mov,mp4,m4a,3gp,3g2,mj2" ) != 0 )
+                    {
+                        pv->ignore_pts = 1;
+                    }
+                }
+            break;
+        
             default:
                 pv->ignore_pts = 1;
                 break;