This seems to me as a partial regression of some 'long time ago fixed' bug. The central column of the page has grayed background and it makes gray/white stripes when you scroll. (Linux nightly 20000925)
dup of 53568 "Poor layout, grey backgrounds everywhere" *** This bug has been marked as a duplicate of 53568 ***
Yes it's dup sorry for the spam (I've searched for gray and not grey).