[Forum] sidebar closed / flicker open -> closed when loading page

[boatdesign]

In firefox, with the sidebar closed (on the default style, including here at vbulletin.com) it seems the page first loads with it open and then it quickly "flickers" or reflows to closed as the page loads. It's quick, but creates a noticeable flicker effect for me, or maybe I should say "movement" effect as the page seems to load then move over.

I wonder if there's any way to make it "load closed" when a user has it closed so it doesn't have to "move over" visibly each time the page loads for them.