Contacts won’t sync with Outlook/hotmail.com from android phone (using MS exchange activesync). Email and calendar sync fine.

For some reason my phone has stopped syncing contacts to my hotmail account from my android phone using microsoft exchange activesync.  This used to work fine and I have not changed any settings.  The phone seems to think that a sync has taken place (which works fine for email and calendar items) but new or updated contacts don't appear in my hotmail address book on a PC. 

Can anyone help please?