iCloud on OS X 10.9.2 not allowing me to select Calendar or Contacts to allow syncing

Hi

I have OS X 10.9.2 and previously had Calendar/Contacts/Reminders selecting for syncing to my iOS devices via iCloud. I noticed my calendar updates were not syncing today, so went into the OSX settings and found that Calender/etc were no longer selected.

I tried selecting again, and my Mac just shows the message 'setting up', but then does nothing and the tick I added to the app disappears (ie, it is not allowing me to select calendar etc for syncing with iCloud).

I have done the basics of confirming the correct accounts are selected on the iOS devices and the Mac, however don't know what else to do. Can anyone else help?

Cheers, Craig