Getting continual MYDEBUG files with messages similar to the following. Any ideas on what is causing this? My cache.php file is the standard Zen file.

[23-Sep-2010 20:15:20] PHP Warning: file(/cache/zc_7eb4ed1f36d90140477d9474b61e0e26.sql): failed to open stream: No such file or directory in /includes/classes/cache.php on line 149
[23-Sep-2010 20:15:20] PHP Warning: implode(): Invalid arguments passed in /includes/classes/cache.php on line 150
[23-Sep-2010 20:15:20] PHP Warning: Variable passed to each() is not an array or object in /includes/classes/db/mysql/query_factory.php on line 127
[23-Sep-2010 20:15:20] PHP Warning: session_start(): open(SESSION_WRITE_DIRECTORY/sess_0b0v1vu190brv2o1294si08l51, O_RDWR) failed: No such file or directory (2) in /includes/functions/sessions.php on line 114
[23-Sep-2010 20:15:20] PHP Warning: Unknown: open(SESSION_WRITE_DIRECTORY/sess_0b0v1vu190brv2o1294si08l51, O_RDWR) failed: No such file or directory (2) in Unknown on line 0
[23-Sep-2010 20:15:20] PHP Warning: Unknown: Failed to write session data (files). Please verify that the current setting of session.save_path is correct (SESSION_WRITE_DIRECTORY) in Unknown on line 0

-lindasdd