#39 close issue error

[Anonymous]

whenever an issue needs to be closed i get the following error:

Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /var/www/apps/projectbench/bugtracking/closebug.php:1) in /var/www/apps/projectbench/bugtracking/closebug.php on line 28

any ideas? thank you in advance