Page SHifts in Firefox/Need Scrollbar

On my site the page shifts in firefox when scroll bars appear. Does anyone know how to fix this?

A url to your page??

that is normal firefox behavior happens with every site, when a scrollbar is needed firefox needs space to render it so your page has less space and needs to move over to be in the center again. it wont happen if you have the page justified to the left.

it doesn't happen in IE because there is always a space reserved for the scrollbars, have a look and on a site without scroll bars you will see a blanked out scrollbar.

I added the following to the css style sheet. I would thik it would be standard but its not. Most Zen Cart websites need scroll bars.

ADD TO STYLE SHEET:

body {
overflow-y: scroll;
}