sessions path incorrect

Im getting this error whenever I try to use sessions with PHP4.0.1pl2 apache module under RedHat Linux. This is the production server, on my developing server it works fine, only difference is that im using SuSE linux here. "PHP Warning: Failed to write session data. Please check that the current setting of session.save_path is correct (/tmp) in Unknown on line 0" Ive tried customizing the session handler to use mysql and everything works fine, but I still need the files handler for smaller projects. Ive check the /tmp directory and its there with permissions for everybody. Ive noticed that session files are created with a length of zero. Ive had a look in the bugs database and theres something about sessions not working when you dont register any variables. This is not the case because there is always a variable being registered. Could someone throw any light on this subject? Regards, David Garcia Watkins