Not quite working

Hiya - I know it's a dev release, but I'm trying to use addnode 5.x.2.x-dev and it's got some issue- I haven't checked 'multiple values' in my field creation form, but it's still displaying a multiselect box instead of a single pulldown, and there seems to be a broken image under the field label, and the 'popup' isn't quite working, either, but I guess that's because I didn't install thickbox yet? Should probably add a module dependency?

I attached a screenshot of what I'm seeing with broken image.

Thanks! This module is SO useful, I'm really excited that it's being rewritten.