Rendering error in Chrome/Opera with small-screen layout

[olslash]

reproduce:
Drag the Chrome window to mobile-width or use device mode to select a mobile screen size.
Load the page.
-Button panel does not appear. Revisions do not appear.
Resize the page width by a pixel or two
-Page re-renders as normal.
type in the text editor and click 'save'
-Page does not update to show the new revision
Resize the page width by a pixel or two
-Page updates.

commenting out

main-container

height: 100%

messes up layout, but fixes this issue.

Issue only exists in Chrome and Opera-- Safari and Firefox work fine.