Redmine

When the settings "Project menu tab for creating new objects" is set to 'Display the "+" dropdown", all the drop down menu items are displayed as tab.
Each 'new' option is working fine.
It happens after an update from 2.5.2.devel to 3.3.1.stable. and I see it on every browser i tried... and it's a lot of browser!

See the attached screenshot

Environment:
  Redmine version                3.3.1.stable
  Ruby version                   2.1.5-p273 (2014-11-13) [x86_64-linux-gnu]
  Rails version                  4.2.7.1
  Environment                    production
  Database adapter               Mysql2
SCM:
  Subversion                     1.8.10
  Mercurial                      3.1.2
  Git                            2.1.4
  Filesystem                     
Redmine plugins:
  no plugin installed