Index: /trunk/ccl/lisp-kernel/lisp-debug.c
===================================================================
--- /trunk/ccl/lisp-kernel/lisp-debug.c	(revision 660)
+++ /trunk/ccl/lisp-kernel/lisp-debug.c	(revision 661)
@@ -19,4 +19,5 @@
 #include "lisp_globals.h"
 #include "area.h"
+#include "Threads.h"
 #include <ctype.h>
 #include <stdio.h>
@@ -630,4 +631,8 @@
   va_list args;
 
+  if (threads_initialized) {
+    suspend_other_threads();
+  }
+
   va_start(args,message);
   debug_command_return state = debug_continue;
@@ -651,8 +656,12 @@
   switch (state) {
   case debug_exit_success:
-    resume_other_threads();
+    if (threads_initialized) {
+      resume_other_threads();
+    }
     return 0;
   case debug_exit_fail:
-    resume_other_threads();
+    if (threads_initialized) {
+      resume_other_threads();
+    }
     return -1;
   case debug_kill: