The problem is, that the user creation in the forum is disabled (because of spam and abuse).
The only why to create a forum account is to ask for forum account while registering a template account on any host.
The forum normally updates the counters... but I could not manage to make this when creating the new user in the database direcly. The solution is there - I read the code - but for some reson it does not work.
In the Board admin menu - need to run "Resynchronise statistics" - that fixes the problem.
If somebody tell me what more should I update in the database in order this to work - I would be very thankful.
PS: I already spent several hours reading this function, mimic what it does in the database - regardless the Board respons just when run from the admin menu "Resynchronise statistics". Means I do not understand something