Breaks Vertical Tabs

The popular vertical tabs module apparently breaks under this theme. Some of the fieldsets that are supposed to be moved into vertical tabs instead appear underneath the vertical tabs, even though the vertical tabs have a section for them.

See screenshot for example. Note how "Authoring Information" has a vertical tab section, but it's empty, and there's also a collapsible fieldset underneath it for the same section.

To reproduce:

- Enable vertical tabs
- Enable this admin theme (and make it the default for adding/editing content)
- Go to /node/add/page and observe