Template moves when chaging width

We recently had to upgrade a site from Joomla 1.5 to 2.5 and with it the template.
Everything was working fine until we changed the site width to 1000px.
Everything jumped out of the framework and the site ended up looking like this:
http://www.mushroominfo.co.za/jupgrade

When we changed the width of the template back to 980px it stayed like that.
Does anybody know what we can do in order to fix this?

Thank you!

You can add following css code to your override.css and enable css override option in template settings > advanced settings > css override "on".

Change 1000px to your required width.

Code: Select all

body {
    margin-left: auto;
    margin-right: auto;
    width: 1000px!important;
}


See you around...