--- old/src/share/vm/utilities/debug.cpp	2010-11-18 08:15:18.595216314 -0800
+++ new/src/share/vm/utilities/debug.cpp	2010-11-18 08:15:18.150851804 -0800
@@ -361,8 +361,14 @@
 extern "C" void disnm(intptr_t p) {
   Command c("disnm");
   CodeBlob* cb = CodeCache::find_blob((address) p);
-  cb->print();
-  Disassembler::decode(cb);
+  nmethod* nm = cb->as_nmethod_or_null();
+  if (nm) {
+    nm->print();
+    Disassembler::decode(nm);
+  } else {
+    cb->print();
+    Disassembler::decode(cb);
+  }
 }