Re: Page "positioning"
There's not a lot you can do, other than forcing the scroll bar to appear on your "rogue" page by, say, inserting a transparent image or an empty element with a defined height. It's a matter of cross-browser and cross-platform differences -- you can't know the exact width of the scroll bar, so you can't make allowances for it for pixel-perfect presentation. Using CSS alone you can force both scrollbars with overflow: scroll;, but the horizontal scrollbar is going to be confusing to your users (especially given that the "thumb" is not going to appear if the content isn't wide enough to overflow the viewport) and, well, it's a bit ugly.
I wouldn't worry about it. What if you fix that one page and somebody goes to your site with a really high-rez monitor pivoted to vertical (with the screen taller than it is wide)? Leave it be -- it's working the way it's supposed to.
“Beware of bugs in the above code; I have only proved it correct, not tried it.” --Donald Knuth
"It was as if its architects were given a perfectly good hammer and gleefully replied, 'neat! With this hammer, we can build a tool that can pound in nails.'" -- Alex Papadimoulis (on TheDailyWTF.com)