[2.2] UI regressions on machine listing page

This is with the latest code on trunk; revision 5909.

I noticed two critical issues on the machine listing page.

(1) If I select one or more machines and click the "Take action" drop-down, I can see the first 3 or so options, and the rest seem to have plunged underneath another element on the page.

(2) If I resize the browser window, the header area isn't resizing with the rest of the window.

See screenshot for a visual.

I'm guessing this has to do with the CSS changes in revision 5905, because I didn't see this while testing earlier today