Select Box Click Causing Jump To Top Of Page

Anywhere on my pages where there is a select box (drop down), like on the My Account page for billing state, for example, when I click on the select box, I jump up to the top of the page. I can't figure out what's going on or how to fix that! It must be javascript somewhere causing it. I can see when I view source that there is actually a link () that represents the drop down. I can't find this code anywhere to modify it so that it's a real drop down and doesn't execute any javascript upon click.