Weekends and non-working days are displayed in burndown chart

Hi guys

Greenhopper configuration says 'GreenHopper will take for granted that the weekends are non-working days'

https://confluence.atlassian.com/display/GH/Specifying+your+GreenHopper+General+Configuration

but as you can see in the attachment, 12th of October (defined as non-working day in Spain) and 13th and 14th of October (weekends) are displayed in our burndown.