Photo Upload in Posts for other Roles

I can upload photos (and other media) as admin across all blogs. It appears that users on my wpmu site are unable to do so. I have logged into a site as the role of site admin and have confirmed that the menu options for uploading media is checked in the "options" section of the Admin>Site Options, but they do not show up above the tinymce interface. Also, when a user clicks on the photo upload button (the little tree picture) in the tinymce editor loads a window that is blank (again, only for user roles including admin) it shows up for the main admin login.
Any ideas? I'm sure I've got it turned off somewhere or something. Thanks for the help!

-james