Problem with Theme Options menu


I have a strange problem here - under Appearance -> Theme Options, I can only see the first tab - (#tab1) allowing me to change the adminbar background colour. This is still functional. If I click on any of the other tabs, the URL changes (eg adds the target #tab<x> on the end), but nothing happens.

It was working before, and I've made a few changes recently, and I'm having trouble working out which change has caused the problem. I'm using Nginx, and I've just enabled caching (following this guide: but I tried changing all that back and it didn't help. I've looked in the debug console, and I found this:

Uncaught TypeError: Cannot read property 'length' of undefined load-scripts.php?c=1&load%5B%5D=jquery-core,jquery-migrate,utils&ver=3.6.1:3
x.extend.each load-scripts.php?c=1&load%5B%5D=jquery-core,jquery-migrate,utils&ver=3.6.1:3
e.widget load-scripts.php?c=1&load%5B%5D=hoverIntent,common,admin-bar,heartbeat,wp-a…raggable,jquery-ui-button,jquery-ui-position,jquery-ui-dialog&ver=3.6.1:21
(anonymous function) load-scripts.php?c=1&load%5B%5D=hoverIntent,common,admin-bar,heartbeat,wp-a…raggable,jquery-ui-button,jquery-ui-position,jquery-ui-dialog&ver=3.6.1:25
(anonymous function) load-scripts.php?c=1&load%5B%5D=hoverIntent,common,admin-bar,heartbeat,wp-a…raggable,jquery-ui-button,jquery-ui-position,jquery-ui-dialog&ver=3.6.1:25

I've tried restoring the database to a backup from this morning, but that didn't have any effect. Bad things happened next, and I had to blow away and rebuild my wp-config.php file, but I've got it back to where it was before.

The problem occured in Chrome and Firefox, so I'm guessing it's not a browser issue. I've tried clearing cookies/caches etc.

My guess is it's something to do with jquery not loading somewhere. Do you have any ideas that might help point me in the right direction?