datepicker wraps the month select arrows to 2 lines

datepicker wraps the month select arrows to 2 lines

My datepicker calendar displays but wraps the top arrows onto 2 lines and flickers the calendar on mouseover. 

The code is in Rails as <%= f.text_field :nomination_fee_paid_date, :id => "datepicker" %> and the output is

<input id="team_nomination_fee" name="team[nomination_fee]" size="30" type="text" />