setcookie expects at most 6 parameters, 7 given in

I am using php 5.1.6 on Centos5.4 32bit,apache 2.2.3,Install the dolphin 7 RC2,after insatllation,every thing seems ok，

after creating the first user i got this error when i want to login,then redirect the member.php,i can't login.

In the apache error_log,i find this error:

" PHP Warning:  setcookie() expects at most 6 parameters, 7 given in inc/profiles.inc.php on line 457,"

how can i fix this ?

You need at least PHP Version 5.2.0 to run Dolphin 7. This will probably resolve your issue with authentication.

Chris

thx