Hi all We are having problems with our Grandstream BT100 and handytones phones with the latest firmware. Those phones with firmware 1.0.4.50 the server is able to talk to them and there is no one way audio problem For softphones there is no such problem For phones with the latest firmware (1.0.5) there is one way audio. When I send an OPTIONS SIP method to one of them I get 400 (Bad Request) from those phone while when I do the same thing on a phone with previous version I get 200 OK message . Here is a sipsak trace to the phone # 04400112 which has 1.0.5 firmware As you can see it the last message received is 400 (Bad Request) while it should be 200 OK as the message below This message was sent to 04400202 which is a handytone 286 with 1.0.4.5 firmware I am able to call the phone below and from these two to any other softphone but the one above gives me one audio And again the HandyTones I talked about last time still do not work. Any idea of what is wrong? Regards,