[jQuery] using cycle for website navigation, choppy in firefox

[jQuery] using cycle for website navigation, choppy in firefox

I am creating a website for my company.  I am using the cycle plugin to
navigate horizontally between pages.  The plugin is awesome.  However
the site is starting to get pretty full and I've just added something
that has made the cycle navigation choppy, just in firefox.  The site
is not public so I don't have a URL.  But I just added a div to the
page to allow for some internal scrolling which seemed to be the cause
of the choppiness.
Here is the CSS for the div that I just added that made the site choppy.  This div goes inside of the div that gets cycled.
.scrolling {
    overflow-y: auto !important;
    position: absolute;
    width: 100%;
    height: auto;
    top: 270px;
    bottom: 0;
}
Is there something obvious in here that might be causing the problem?  Or do I need to show more code?
Thank you very much.
Mike