Index: wireshark-1.4.6/epan/dissectors/packet-isakmp.c
===================================================================
--- wireshark-1.4.6/epan/dissectors/packet-isakmp.c
+++ wireshark-1.4.6/epan/dissectors/packet-isakmp.c	2011-10-20 14:21:12.426597819 +0200
@@ -3796,14 +3796,14 @@
   offset += 2;
   length -= 2;
 
-
+  if (spi_size > 0) {
   while (length > 0) {
          proto_tree_add_item(tree, hf_isakmp_delete_spi, tvb, offset, spi_size, FALSE);
          offset+=spi_size;
          length-=spi_size;
  }
 }
-
+}
 
 static void
 dissect_vid(tvbuff_t *tvb, int offset, int length, proto_tree *tree)