diff -urbp apr-util-1.3.9/misc/apr_thread_pool.c apr-util-new/misc/apr_thread_pool.c
--- apr-util-1.3.9/misc/apr_thread_pool.c	2009-09-15 15:48:28.000000000 -0400
+++ apr-util-new/misc/apr_thread_pool.c	2009-09-25 08:42:12.000000000 -0400
@@ -379,7 +379,12 @@ APU_DECLARE(apr_status_t) apr_thread_poo
                               apr_pool_cleanup_null);
 
     while (init_threads) {
+        /* Grab the mutex as apr_thread_create() and thread_pool_func() will 
+         * allocate from (*me)->pool. This is dangerous if there are multiple 
+         * initial threads to create. */
+        apr_thread_mutex_lock((*me)->lock);
         rv = apr_thread_create(&t, NULL, thread_pool_func, *me, (*me)->pool);
+        apr_thread_mutex_unlock((*me)->lock);
         if (APR_SUCCESS != rv) {
             break;
         }