[Post-nuke-users] not working for me

[nagendra p. <tn_...@re...>]

hi,
i ahve installed pn703 on my linux box.
when i use the admin uid & pwd to login thru the  home
page,
i get a warning like
"""" Warning: Cannot add header information - headers
already sent by (output started at
/var/www/html/postnuke/html/config.php:414) in
/var/www/html/postnuke/html/modules/NS-users/tools.php
on line 35
Logging You in Hang Tight ! """"
after seeing this error the error vanishes & the whole
page dispalys (the same page where i type the uname &^
pwd )
this error is not only for admin but for also all
anyother users.
but i find the members list in the database & also when
i click the link members list

but when i chexck the line no. 35 in the file tools.php
its

    setcookie("user","$info",time() + 15552000);

i'm completely struck up.
plz help me
i badly need ur help.
in vain......................
prasad