session.save_path problem again

Hi, I'm sorry, I know this is a commonly asked question, but I've checked every suggestion offered here and in other groups/lists. Yet, I still get "Failed to write session data (user). Please verify that the current setting of session.save_path is correct (/tmp/php)" I have save_path set to "/tmp/php" in php.ini. This directory exists and is owner/group/world writable. There is even a single session file already present in the directory (I suspect it was created when I tried turning on session.auto_start; unfortunately postnuke didn't want to work with that setting on). I'm running PHP 4.1.2/Apache 1.3.26 on MacOSX 10.1.5 Server. Any thoughts? Thanks Dmitry