[问]：Warning: Cannot modify header information

unknownu

错误信息如下：
1. Warning: main(../config.php): failed to open stream: No such file or directory in
2. Warning: main(): Failed opening '../config.php' for inclusion (include_path='.:/usr/share/php:/usr/share/pear') in
3. Warning: Cannot modify header information - headers already sent by (output started at
4. Warning: session_start(): Cannot send session cookie - headers already sent by (output started at
5. Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at
6. Fatal error: Call to undefined function: mysql_pconnect() in

问题：
同样的代码在 Slackware 10.0 上运行无误，可在 Debian 3.0 testing上就出现了上述问题。

不知何故，请教。