[_ck_]

Hidden Forums has not been tested yet again 1.0 alpha.

I simply don’t have time to modify every plugin for all the changes.

This is why people should not use the alpha yet for regular sites.

Update: I’m unable to reproduce your problem however.

I have no extra queries with using Hidden Forums on the 1.0 trunk. Are you using the Alpha from the download on bbpress.org, or are you using the SVN trunk?