Page Jumps

Hi,
This works quite fine on this site: http://www.confidenthorserider.co.uk/choose-your-membership/

However, it seems that each time a tab is rolled-over, the page jumps back to the top which is a little disconcerting.
Is there a way to resolve the page jumping?

Thanks

http://ww.wp.xz.cn/plugins/rollover-tab/