iCloud items in preference pane greyed out in Yosemite
As a lot of people I have upgraded to Yosemite and almost everything seems to work.
However, I seem to have some problems related to iCloud. In the iCloud preferences pane all of the items such as iCloud Drive, Mail, Address Book and so on are greyed out. There's this tiny litte button on top which I can click and submit my iCloud password but it does not get the items to become clickable/whatever.
Is this a bug? According to this page https://www.apple.com/support/systemstatus/ everything seems to be working ay-okey...
Please advice.
MacBook Pro (Retina, 15-inch, Late 2013), OS X Yosemite (10.10)