The iOS was updated, also iTunes
I tried restoring to an earlier date but that didn't help, then I restored the iphone as a new iPhone, which wiped out photos and apps, but that's ok.
Then deleted Itunes and iCloud off the Dell and reinstalled both.
Have just noted that new contactes added to outlook are not synched either. I normally use Outlook and synch to the phone.
I have checked the setup on the phone and on the iTunes site and both seem ok to me.