The inline stylesheet served in the head of each wikipedia page has a media=screen attribute in its declaration. This is problematic in Opera when you hit F11 to take the browser to full-screen mode, which uses media=projection (a handy replacement for powerpoint, as it happens). The styles within that sheet are ignored, and since it contains the margin for the main div, the main and left divs overlap rather messily. Print preview shows the same overlapped rendering.
Unfortunately media="screen,projection" results in the stylesheet being ignored in Netscape4 and IE4 (an oft-used hack for hiding style from these browsers). Is the intention of the media=screen to disable the style for print, or merely to be standards compliant?
The best solution might be to declare the stylesheet with no media attribute. In fact, inclusion of a media="print" stylesheet to follow it with the rule #quickbar {display:none;} would allow printing without having to laod the "printable version" - which has fonts that are too large IMO (I can cope with smaller fonts printed than I can on screen). Most of the features of the current printable page can be achieved via css2, including the citation at the bottom.