Sailfin b15. NB 6.0 with SIP Test Agent.
I've added new headers to the requests (clicked Add and selected a new header
from the list). Then I've tried to remove the headers that I've just added. I've
selected such header and clicked Remove. Then I did not see this header in the
list but at the right side under Message Preview I still saw the deleted header
and when I've sent the message, this deleted header was sent. When after Send
I've created the same new message I again saw the deleted header. Only when I
clicked Cancel these deleted header gone.
And I absolutely was not able to Remove the default headers.