The Media buttons don't load in there pop-up lightbox, instead they reload the page filling with the upload tool and destroying my post. I can't upload anything because it goes no where. this happens on all my MU installs. I'm using Firefox 3.5 and flash 10.
hm, can't think of a solution right now, but I'd be curious if this plugin solves your problem: http://wordpress.org/extend/plugins/faster-image-insert/
it works just fine on my wpmu 2.7.1 installation ;-)
Ditto. You don't have any sort of pop up blocker in Firefox, do you? Have you tried a different browser? Anything in the webserver's error logs? (I doubt there is but that's really is a first step and you never know.)
Wouldn't surprise me if this was yet another issue with Flash 10.
the plugin I suggested CAN turn off the thickbox loader,that is why I suggested it... :-)