--- chan_sip.c.orig	2009-03-19 10:10:13.000000000 +0100
+++ chan_sip.c	2009-03-19 13:09:28.000000000 +0100
@@ -6524,11 +6524,6 @@
 	expire = strchr(buf, '~');
 	if (expire)
 		*expire++ = '\0';
-	callback = strchr(buf, '/');
-	if (callback)
-		*callback++ = '\0';
-	if (ast_strlen_zero(callback))
-		callback = "s";
 
 	sip_parse_host(buf, lineno, &username, &portnum, &transport);
 
@@ -6536,6 +6531,11 @@
 	hostname = strrchr(username, '@'); /* allow @ in the first part */
 	if (hostname)
 		*hostname++ = '\0';
+		callback = strchr(hostname, '/');
+		if (callback)
+			*callback++ = '\0';
+		if (ast_strlen_zero(callback))
+			callback = "s";
 	if (ast_strlen_zero(username) || ast_strlen_zero(hostname)) {
 		ast_log(LOG_WARNING, "Format for registration is [transport://]user[:secret[:authuser]]@domain[:port][/extension][~expiry] at line %d\n", lineno);
 		return -1;