--- chan_sip.c.orig	2005-08-19 02:21:08.000000000 -0600
+++ chan_sip.c	2005-08-19 02:26:30.000000000 -0600
@@ -9569,7 +9569,7 @@
  					p->subscribed = CPIM_PIDF_XML;    /* RFC 3863 format */
  				} else if (strstr(accept, "application/pidf+xml")) {
  					p->subscribed = PIDF_XML;         /* RFC 3863 format */
- 				} else if (strstr(accept, "application/xpidf+xml")) {
+ 				} else if (strstr(accept, "application/xpidf+xml") || strstr(p->useragent, "Polycom")) {
  					p->subscribed = XPIDF_XML;        /* Early pre-RFC 3863 format with MSN additions (Microsoft Messenger) */
 				} else {
  					/* Can't find a format for events that we know about */