I have been syncing my contacts successfully for some time between my Windows 8 computer running Outlook under Office 2010, my live.co.uk account online and my HTC 1X+ smartphone using Exchange ActiveSync.  A few days ago a number of contacts disappeared from my phone and no matter what I try, I cannot get them back.

I have removed the ActiveSync configuration and re-created it many times.  I have even hard reset my HTC and started again but the same contacts are still not being copied over to the phone.

I can make changes (add/modify/delete) on my computer and these are synched up to my People in my live.co.uk account and vice verse.  Some changes and deletions appear to get through to my HTC but definitely no Adds.  However, I can add a contact on my HTC which is then sync'd to my live.co.uk account and onwards to my computer.  If I try to add names which did not get sync'd I end up with two entries with the same name in my live.co.uk People list and in my Outlook Contacts on my computer.

Some Entries appear be being duplicated and triplicated in the contacts on my phone

The sync process in Exchange ActiveSync on my HTC will show "Syncing now..." for  several minutes for Contacts but is almost instant for Calendar, Mail and Tasks.  Often it fails with the message "Sync is currently experiencing problems.  It will be back shortly."

I'm not sure if it is significant or coincidental but the contacts which disappeared from my phone appeared to be those I called or who called me as their names disappeared from the call history, leaving just the phone number.  I even thought that may have been the cause of the problem and deleted the whole of my call history.

I am at my wit's end because, as mentioned, I am missing contacts that I phone regularly.