Someone at NYPL had some trouble building exhibits in Omeka 0.9.0, using Internet Explorer 6.0.2900.2180 (SP2). His comments:
"I'm having problems saving any edits I make to the page layouts (ordering of images, page text formatting, etc.). I'm able to add individual images to the archive and to edit metadata for these images, but can't save changes related to the exhibition pages themselves."
He switched to Firefox, and everything works fine, but I figured I'd mention this here.