I like to see my calendar in a month's view and Week starts on Sunday.

Ok I've set it properly.

The problem is, it somehow goes back to week starts on Monday.

Any IDEA why????

its a bug.......

evrytime you seit it... it will go back to the default settings.....

mine is working fine even after changing the start day of the week...... its accepting the change :)

I think when you change your theme, it goes back to the original settings.