Steps to reproduce:

1. Login to backoffice.
2. Go to Admin / Content Type / Content.
3. Add new CT with field ezselection (add several options to it's fieldtype).
4. Create new content based on previously added CT (step 4).
5. Expand dropdown. 

Actual result:

See attachment.

Dropdown is not properly styled for content type with field ezselection

Expected result:

Properly styled dropdown.