Resizing TOC in FireFox error

If the user resizes the Table of Contents in my site, the Contents, Search, Glossary toolbar appears twice and the TOC will no longer bring up topics. Refreshing the browser fixes it and sets the TOC back to the starting width. Is the user supposed to be able to drag the TOC boundary and make the TOC wider or narrower?

This problem is in FireFox only. It works fine in IE

Here’s my site: http://feathelptemp.spatialdynamics.com/

Thanks!
http://feathelptemp.spatialdynamics.com/