Same problem in v1.35NA. I couldn't find how to load the page without CSS in Chrome. But the Tools | Developer tools dialog was a nice way to do it: open the dialog while viewing the Admin page, click the magnifying glass (bottom left) then the Admin header element, expand the "fieldset" and you'll notice a "p" html element that has display:none, uncheck it to disable that CSS and you'll see the Timeout field appear, you can edit the setting and save.