Index: /trunk/Ohana/src/libohana/src/IOBufferOps.c
===================================================================
--- /trunk/Ohana/src/libohana/src/IOBufferOps.c	(revision 13550)
+++ /trunk/Ohana/src/libohana/src/IOBufferOps.c	(revision 13551)
@@ -108,6 +108,9 @@
   int Nbyte;
   char tmp;
+  va_list argp2;
 
-  Nbyte = vsnprintf (&tmp, 0, format, argp);
+  va_copy (argp2, argp);
+
+  Nbyte = vsnprintf (&tmp, 0, format, argp2);
 
   if (buffer[0].Nbuffer + Nbyte + 1>= buffer[0].Nalloc) {