diff -urNb nmap.orig/nse_main.lua nmap.new/nse_main.lua
--- nmap.orig/nse_main.lua	2015-02-20 04:27:28.261799000 +0000
+++ nmap.new/nse_main.lua	2015-02-20 14:20:15.093476000 +0000
@@ -321,6 +321,15 @@
   end
 end
 
+-- Get a consistent string representation of a coroutine: lower case hex chars.
+local function co_string(co)
+  local id = match(tostring(co), "thread: (.*)");
+  if id:sub(1, 2) == "0x" then
+    id = id:sub(3);
+  end
+  return id:lower();
+end
+
 -- The Script Class, its constructor is Script.new.
 local Script = {};
 -- The Thread Class, its constructor is Script:new_thread.
@@ -467,7 +476,7 @@
       co = co,
       env = env,
       identifier = tostring(co),
-      info = format("%s M:%s", self.id, match(tostring(co), "0x(.*)"));
+      info = format("%s M:%s", self.id, co_string(co));
       parent = nil, -- placeholder
       script = self,
       type = script_type,
@@ -485,7 +494,7 @@
       args = pack(...),
       close_handlers = {},
       co = co,
-      info = format("%s W:%s", self.id, match(tostring(co), "0x(.*)"));
+      info = format("%s W:%s", self.id, co_string(co));
       parent = self,
       worker = true,
     };