Best Answer Simon_P , 08 February 2013 - 07:40 PM
One of your plugins is using an out of date jquery library. This happens every time wordpress update the core libs, it takes the plugin authors several months to realise and update.
Even though plugin/theme authors are notified months in advance lol.
So go thorough all your plugins and make sure they are all up to date, and if problem persists try the following:
1. clear your browser cache ( you may have the old jquery cached localy )
2. reupload wordpress files ( all except the wp-content folder )
Hopefully that will fix it.Go to the full post