--- chan_sip.c-orig	2005-09-14 10:56:21.000000000 +0200
+++ chan_sip.c	2005-09-14 11:03:48.000000000 +0200
@@ -11094,7 +11094,7 @@
 	} else if (!strcasecmp(v->name, "progressinband")) {
 		ast_set_flag(mask, SIP_PROG_INBAND);
 		ast_clear_flag(flags, SIP_PROG_INBAND);
-		if (strcasecmp(v->value, "never"))
+		if (strcasecmp(v->value, "never")&&!ast_true(v->value))
 			ast_set_flag(flags, SIP_PROG_INBAND_NO);
 		else if (ast_true(v->value))
 			ast_set_flag(flags, SIP_PROG_INBAND_YES);