I sometimes get this error where the forum switches to a blue/white one with this error written:
Warning: include(./cache/board_config.php) [function.include]: failed to open stream: No such file or directory in /nfs/c08/h01/mnt/119400/domains/zoolook.nl/html/forum/common.php on line 250
Warning: include() [function.include]: Failed opening './cache/board_config.php' for inclusion (include_path='.:/usr/local/php-5.2.14/share/pear') in /nfs/c08/h01/mnt/119400/domains/zoolook.nl/html/forum/common.php on line 250
Warning: Cannot modify header information - headers already sent by (output started at /nfs/c08/h01/mnt/119400/domains/zoolook.nl/html/forum/common.php:250) in /nfs/c08/h01/mnt/119400/domains/zoolook.nl/html/forum/includes/sessions.php on line 546
Warning: Cannot modify header information - headers already sent by (output started at /nfs/c08/h01/mnt/119400/domains/zoolook.nl/html/forum/common.php:250) in /nfs/c08/h01/mnt/119400/domains/zoolook.nl/html/forum/includes/sessions.php on line 547