I've set up a group with a handful of fields ... mostly textboxes, some dropdowns, and one related ... on a custom post type defined in another plugin. Five or six of the fields are defined as required.
When I edit the custom post in IE8 the required field validation doesn't happen and I'm able to save the post without entering values in those fields.
When I edit using Firefox 11 the required validation works as expected.
Any suggestions? (other than not using IE that is ;-)