We have had serious problems with duplication of contacts recently... One of the 'issues' seems to be that MPE 1.8.6 fails to properly transfer the 'flag' ("This is the mailing address") to identify which address is the mailing address. I've seen Outlook start by displaying the mailing address in the 'Address Card' view, but it disappears after sync with phone. The address is still there, but no longer shows on the Address Card view... I'm also seeing that 'United States of America' is being added to some addresses - such that I end up with two (or more) contacts each with differing 'mailing address' and/or country...
Another strange issue, has been that MPE fails to 'see' certain new Calendar events in the phone. The only way to force them to cross over to Outlook is to manually change something (i.e. description), and presto, the event syncs as one might expect. We turned OFF any contacts/calendar sync with Google long time ago, so don't think that is a factor.
Any thoughts/suggestions would be appreciated. Thanks