I just helped someone having this exact same issue. They were using the plugin to rotate images in the header image area of Twenty Ten. The slideshow and the site-title were conflicting and it was pushing the slideshow way over to the right in Firefox. They already had a child theme set up.
The plugin wraps the slideshow with a div with an ID of rotator. All that needed to be done to fix the problem was add the following to the child theme stylesheet. Even though the plugin embeds styles for "#rotator" it doesn't include the clear property, so there is no problem with this being overridden by the embedded styles.
This made the slideshow drop below the site-title and everything was fine. It caused no problems in other browsers.