diff -urN asterisk-1.6.2.11_old/channels/chan_sip.c asterisk-1.6.2.11/channels/chan_sip.c
--- asterisk-1.6.2.11_old/channels/chan_sip.c	2010-08-17 18:04:36.000000000 +0200
+++ asterisk-1.6.2.11/channels/chan_sip.c	2010-08-17 18:04:46.000000000 +0200
@@ -20058,6 +20058,26 @@
 			} else {
 				p->jointcapability = p->capability;
 				ast_debug(1, "Hm....  No sdp for the moment\n");
+				/* Some devices signal they want to be put off hold by sending a re-invite
+				   *without* an SDP, which is supposed to mean "Go back to your state"
+				   and since they put os on remote hold, we go back to off hold */
+				if (ast_test_flag(&p->flags[1], SIP_PAGE2_CALL_ONHOLD)) {
+					ast_queue_control(p->owner, AST_CONTROL_UNHOLD);
+					/* Activate a re-invite */
+					ast_queue_frame(p->owner, &ast_null_frame);
+					/* Queue Manager Unhold event */
+					append_history(p, "Unhold", "%s", req->data->str);
+					if (sip_cfg.callevents)
+						manager_event(EVENT_FLAG_CALL, "Hold",
+							      "Status: Off\r\n"
+							      "Channel: %s\r\n"
+							      "Uniqueid: %s\r\n",
+							      p->owner->name,
+							      p->owner->uniqueid);
+					if (sip_cfg.notifyhold)
+						sip_peer_hold(p, FALSE);
+					ast_clear_flag(&p->flags[1], SIP_PAGE2_CALL_ONHOLD); /* Clear both flags */
+				}
 			}
 			if (p->do_history) /* This is a response, note what it was for */
 				append_history(p, "ReInv", "Re-invite received");