Timer didn't stop

Hi, i start a Timer (step 1 sec.) the timer should stop after the 15's event. So i added a session value for a counter. After the 15 event timerstop was fired but the timer is still running.

Anyone an idea what could be wrong

regards Dirk

    Procedure UKTI_TimerStart
    is
    Begin
      api_session.add('ImportCounter', 0);
      api_timer.starttimer('tUKTICheckFinish');
    End;

   procedure UKTI_TimerExpired
    is
      v_counter int;
      v_dataimport int;
    Begin

      v_counter := api_session.getvaluenr('ImportCounter');
      api_debug.log('Timercounter: ' || to_char(v_counter));

      select count(*) into v_dataimport from TODAYSimport;

      if ( nvl( v_dataimport ,0)> 0) then
        api_debug.log('Data found: Rows Imported: ' || to_char(v_dataimport ));
        api_timer.stoptimer('tUKTICheckFinish');

        --Do
        UKTI_ProcessDataImported;

      elsif (v_counter > 15) then
        api_debug.log('Break in wait for Data !! ');
        api_timer.stoptimer('tUKTICheckFinish');

      else
        v_counter := v_counter +1;
        api_session.add('ImportCounter', v_counter);

      end if;

    end;