Trying to use Panelizer for a node content type with a panels layout I've got a zen theme, with a sub theme, with a plugins folder enabled in which I have a custom layout. 
I've got panelizer enabled on a content type and I am trying to make that content type use my custom layout, however, when I select the layout for that content type it doesn't seem to use it. Usually devel_themer it looks like the page is still using node.tpl.php, I want to override the whole page with my custom layout. 
Are their any things I should bear in mind using panelizer - stuff I need to disable  /enable.
Panelizer 7.3.1 Panelized content shows in preview, but when I view the live page, it looked like a regular, un-panelized node.

Turned on and off everything I could think of...

Finally, I looked at the Display tab of my content type, and clicked open the Custom Display Settings. I turned OFF "use custom display settings for view modes: Full Content and Teaser". Suddenly my nodes were panelized. Click back on "Full Content", and panels disappear.