NB 6.1, Sailfin b57.
I've opened SIP Test Agent. Pressed a button New Request and selected Publish.
Then I've clicked at Add button and added one new header in the publish request
with a correspondent value (Expires 3600). This new header was at the bottom.
Then I've deleted a default Message Content (Hello World).
After that I saw such request:
I.e. first two lines were Ok, but then
Expires (with no value)
Via became the last header and took Expires value (3600), but Via value just