I remember the first time I used Firefox I was extremely annoyed by the fact that the browser does not always show the scrollbars (like Internet Explorer does). The problem with this is when a page's height is not greater than the available screen height and a users clicks a link to a page that is taller than the available screen height it shifts the entire content area over to accommodate for the scrollbars (which probably take up 15 pixels or so). This is most likely the standards compliant way to display a page and IE has been doing it wrong all along, regardless it is annoying seeing the web page jump back and forth in Firefox.

The Solution:

Fortunately there is a solution using CSS:

html { overflow-y: scroll; }

The Opposite

If the meaning of your life depends on not conforming to Microsoft (you're out there) you can also make IE behave like Firefox:

html { overflow-y: auto; }

Whatever method you prefer I would recommend placing this in your baseline stylesheet before starting a new web site or project. Your users will thank you.