HTC Hero :: HTC Sync Deleting Outlook Contacts

I got HTC Sync set-up to sync up my outlook calendar and contacts. ran it through, and other than truncating address fields to 25 chars, it all worked fine. But then I ran it again, to cehck it was all ok giong forwards (ie expecting no updates), and it:Deleted 32 of my 200 contacts (seemingly at random) from Outlook - left them on the phone. If I manually replace them oon Outlook then duplicates are created on the phone on next sync. Altered 3 recurring appointments (birthdays, 3 out of about 40 in my calendar) in Outlook so that instead of running from midnight to midnight (ie all day events) they run from 23:00 to 23:00, and hence show up over two days. Claimed to have updated a handful more contacts, though I can't see what may have changed. how to avoid? Number 2 is particularly odd. I'm guessing it's something to do with daylight saving, but why only 3 of 40? I've checked the settings against other non-affected appointments, and can see no difference!