PeterD - 6:55 am on May 31, 2003 (gmt 0)

It only happens on pages where a media="screen" statement is used in the CSS. When you hit F11, everything in the media="screen" block is ignored by Opera. (It's looking for a media="projection" block.)

If you don't state your media type in the CSS, then Opera assumes all the attributes apply to all media, so you don't see a change when you hit F11.

I think only very few people specify media types in their CSS, so most pages don't lose formatting when you hit F11. It's ironic that the most conscientious CSS authors are the ones most likely to run into a problem here.