Can’t add categories or send images to editor

I’ve been having trouble adding categories– what will happen is I’ll fill out the blanks and hit the submit button, everything will disappear and the categories won’t be added.

I’m also having trouble uploading photos– sometimes it will, sometimes it won’t, but it pretty much almost never will send them to the editor. I click the button and nothing happens.
So I end up copying and pasting the path of the image to the editor, which kind of defeats the purpose of this whole thing.

I thought it was a browser issue, but I’m having these problems in both Firefox 2.0.0.11 and Safari 3.1.

Help!
Thanks.
http://www.hoorayforever.org/hifrommiguel