After import from Phorum: Wrong post count & user search does not work
 

I have a test installation of the newest vBulletin 3.8 and did an import from an existing Phorum5. The import worked well, but I found two issues:
1. The users post count shows zero for all users. I went through all steps mentionend in the readme file of Impex. But whenever I try to rebuild the post counter in the admin maintenance, it only counts new postings for a user. That means postings a user wrote after the import. All imported postings are not counted.
2. Also these imported postings can not be found when I search for postings or threads of a user. But they can be found, when searching for keywords. New postings (created after the import are found).

What can I do?