>There is some general information at http://helpdeskgeek.com/office-tips/outlook-2010-autocomplete-not-working-or-resetting/ .

Exchange Online moves the pst into an ost. Doing that, it will export and import that into a new or advanced format I assume. When doing so, it seems to forget to bring the related information for those contacts. That seems to be what is causing this. I have been giving a link this morning to try to grab the .nk2 file and move that from one location to another. But, there isn't any .nk2 file anymore.