Calendar week begins with sunday independently from locale

Independently of the locale, the calendar week shown e.g. when selecting a date always begins by sunday.
As we in germany (UK too, as far as I know) begin the calender week by monday, this year the calendar weeks are shifted.
Eg. today (16-Jan-2006) we have CW 3 with german (or UK) locale, but CW 2 with US locale.
As we very heavily use calendar weeks for our shippings, this is a real problem.
I tried changing the locale of the system user starting jira, the field "Default language" in the general configuration of jira,
and my own locale as a user in my user preferences, but no one of these 3 had any effects on the calendar week.
Is there a way in jira to change this?