I upgraded one of my sites, http://www.heapssausages.com, to Wordpress 3.3 recently along with all the plugins I am running and was immediately unable to drag & drop widgets in the dashboard.
I went through the process of disabling and then re-activating all the plugins one by one and discovered that it was Ultimate Facebook causing the problem.
FYI amongst others I am running the following;
Genesis Framework v1.7.1
Landscape Child Theme v1.0.1
Can you help please? I would like to use this plugin!