Media Uploader broken and menu hover flyout not showing

Since upgrading to 3.3 our site won’t let you use the Media Uploader.

-When you click on Select Files, nothing happens.
-When you click on switch to browser uploader, nothing happens, it goes to a #
-When you click the new consolidated upload icon in a post, nothing happens.
-For some reason the new flyout menus do not show as opposed to other 3.3 sites I have worked on. Can this be related?

I DID go through the steps here: http://wordpress.org/support/topic/troubleshooting-wordpress-33-master-list. However, I don’t know how to “flush any caching plugins.”

-I manually reinstalled WordPress 3.3 from the files
-I deactivated all plugins
-I switched to the TwentyTen theme

None of this worked.

Please help asap because uploading media is vital for this website.