Index: /trunk/psLib/configure.ac
===================================================================
--- /trunk/psLib/configure.ac	(revision 9636)
+++ /trunk/psLib/configure.ac	(revision 9637)
@@ -99,5 +99,10 @@
 
 dnl Check for how to link against pthreads
-ACX_PTHREAD([], [AC_MSG_ERROR([pthread support is required to build psLib])])
+dnl RHEL 4.0 was upset about the first arg to ACX_PTHREAD being NULL ([]) so
+dnl we've added in a worthless message to keep it happy
+ACX_PTHREAD(
+  [AC_MSG_RESULT([pthread support is avaiable])],
+  [AC_MSG_ERROR([pthread support is required to build psLib])]
+)
 
 PSLIB_CFLAGS="${PSLIB_CFLAGS=} ${PTHREAD_CFLAGS}"