I have been having an ongoing issue with my BLF lamps on some Aastra 5xi phones where randomly the lamp was not being turned off once the monitored extension hangs up. I ran a sniffer trace and found that the SIP NOTIFY to turn off the lamp was receiving a "SIP STATUS : 500 CSeq Number Out of order" The problem is that any future other calls from the monitored extension does not send any SIP NOTIFY packets after that point. So I cant attempt to fix it by initating another call. Its like it just forgets about the BLF entirely. Any suggestions on this?