This currently happens in case the bar is positioned below the network grid, not within the grid, when there's not enough network resources to fill the height of the view. I'm dropping custom summary bar placement logic altogether, we shouldn't compete with the browser in doing layout.
Original bug report: http://code.google.com/p/chromium/issues/detail?id=73822
Created attachment 84530 [details] patch
Comment on attachment 84530 [details] patch screenshot to follow
Created attachment 84533 [details] [IMAGE] Screenshot with error. Enable filter.
Created attachment 84546 [details] patch
Comment on attachment 84546 [details] patch Clearing flags on attachment: 84546 Committed r80337: <http://trac.webkit.org/changeset/80337>
All reviewed patches have been landed. Closing bug.