2.0.31 shutdown after heavy load

[MATHIHALLI,MADHUSUDAN (HP-Cupertino,ex1)]

Hi,
        I'm getting the following message when I try to stop apache after a
stress-test on HPUX (using webstone).. Inspite of the SIGKILL message, the
process does not exit.. A second attempt is successful.. Any clues regarding
what may be happening is appreciated..

 [error] child process 5891 still did not exit, sending a SIGKILL.


Thanks
-Madhu