I tried removing warning and redirect works ok.
now I can say the problem of seeing other users warnings exist because the user is the starter of the thread and get warning in it !!! (but only in the first page of the thread)
another point
when give a user warning we missed warning level in "Current warnings info:" I think it is important to be there.
again for errors when give a warning with pm, the old version of this hack was ignored pm lenght and if the user can read pm