Error during session_start - is this a bug?

Ok, in testing our site that heavily uses sessions I came across this error: Warning: open(/tmp/sess_f3051699b0f1ae4a89570e66dab05de9, O_RDWR) failed: m (0) in /ora9ias/Apache/Apache/php/cisweb_global.inc on line 19 I can't figure out what causes it. It just happens occasionally when I'm calling a session_start() - does anyone know what this could be? Mike ****************************************************************** This communication is for informational purposes only. It is not intended as an offer or solicitation for the purchase or sale of any financial instrument or as an official confirmation of any transaction, unless specifically agreed otherwise. All market prices, data and other information are not warranted as to completeness or accuracy and are subject to change without notice. Any comments or statements made herein do not necessarily reflect the views or opinions of Capital Institutional Services, Inc. Capital Institutional Services, Inc. accepts no liability for any errors or omissions arising as a result of transmission. Use of this communication by other than intended recipients is prohibited. ******************************************************************