S9 Autoset question

I switched to the climateline hose and full face mask. For some reason the auto start does not come on when I put the full face mask on. I did change the mask setting on the menu to full face so that's not the issue. When I switched back to nasal mask and changed the mask setting back to nasal mask, the auto start comes on.
I first changed to climateline hose.
Then I put the full face mask on that hose and changed the setting to full face mask.
The auto start doesn't come on when I put the mask on.
Now I changed back to the nasal mask and changed the setting back to nasal mask.
The auto start comes on when I put the mask on.

What causes this? Am I doing something wrong?

Also when I'm finished with the clinical menu, is there something I should do to lock the clinical menu again?

I don't think SmartStart works with tthe full face mask. Here's the link.
http://www.resmed.com/ap/assets/documen ... ow_eng.pdf

edit: Sorry, I just realized the link I posted was for the S8, but I think it is the same. I think there is to much volume in a ff mask for the machine to detect your breathing.