I recently discovered a rather bizarre bug that only seems to affect IE7. If you absolutely position italic text of any kind (text made italic through authors styling or something that is styled via the default browser stylesheet such as ems.) IE7 seems to screw up the rendering and ends up creating a horizontal scrollbar. This problem is best illustrated with an example page (View in IE7 to see the horizontal scrollbar). If you override the font-style then the scrollbar dissappears. Strange.
IE6 doesn't have any problem with the same code which is interesting and suggests that this bug has been introduced into IE7.
I also noted that the same problem doesn't exist when the page is rendered in quirksmode.