note 59244 added to function.session-register

I get Warning: session_register(): The session id contains invalid characters, valid characters are only a-z, A-Z and 0-9 ... with session_register() Code is: if(empty($mySession_ID)){ session_name("mySession_ID"); if (session_register("mySession_ID")) { [...] This does not happen all the time. Restarting Apache _seems_ to help for a short while then it happens again. Sometimes it works all just fine and after reloading the page several times I problem pops up. Global sessions settings: session.auto_start Off Off session.cookie_path / / session.cookie_secure Off Off session.name PHPSESSID PHPSESSID session.save_handler files files session.save_path /tmp/session /tmp/session session.use_cookies On On session.use_only_cookies Off Off PHP Version 4.3.3 @ Apache/2.0.54 (Debian) There are less than 1000 session files and the server isn't loaded heavily at all. Searching the web for the error message gives quiet some results but only pages with the same problem... Any ideas? ---- Manual Page -- http://www.php.net/manual/en/function.session-register.php Edit -- http://master.php.net/manage/user-notes.php?action=edit+59244 Delete: added to the manual -- http://master.php.net/manage/user-notes.php?action=delete+59244&report=yes&reason=added+to+the+manual Delete: bad code -- http://master.php.net/manage/user-notes.php?action=delete+59244&report=yes&reason=bad+code Delete: spam -- http://master.php.net/manage/user-notes.php?action=delete+59244&report=yes&reason=spam Delete: useless -- http://master.php.net/manage/user-notes.php?action=delete+59244&report=yes&reason=useless Delete: non-english -- http://master.php.net/manage/user-notes.php?action=delete+59244&report=yes&reason=non-english Delete: already in docs -- http://master.php.net/manage/user-notes.php?action=delete+59244&report=yes&reason=already+in+docs Delete: other reasons -- http://master.php.net/manage/user-notes.php?action=delete+59244&report=yes Reject -- http://master.php.net/manage/user-notes.php?action=reject+59244&report=yes Search -- http://master.php.net/manage/user-notes.php