Index: nse_main.lua
===================================================================
--- nse_main.lua	(revision 19648)
+++ nse_main.lua	(working copy)
@@ -752,12 +752,14 @@
         thread:d("%THREAD_AGAINST threw an error!\n%s\n",
             traceback(co, tostring(result)));
         thread:close(timeouts, result);
+        current = nil;
       elseif status(co) == "suspended" then
         if result == NSE_YIELD_VALUE then
           waiting[co] = thread;
         else
           thread:d("%THREAD yielded unexpectedly and cannot be rerun.");
           thread:close();
+          current = nil;
         end
       elseif status(co) == "dead" then
         all[co] = nil;
@@ -772,6 +774,7 @@
         end
         thread:d("Finished %THREAD_AGAINST.");
         thread:close(timeouts);
+        current = nil;
       end
     end