It seems like values from selects fields are not saved correctly in the session object or maybe they are just not displayed right when you come back to the page.

I assigned a node to two categories, put some text and went to add an image with "Add new" button. Everything went well just that when I posted the image and got back to the original node I was posting, the selected categories were not preserved (other value were ok). Instead the first one was selected which is a default (for required select list).

Was I clear enough?