Error after logout

[Jan Kuipers]

Hello,

I get the following error when logging out. Authentication is done by IMP.

Warning:  Constant sid already defined in /usr/local/apache/htdocs/hordenew/horde/lib/Prefs.php on line 109
Warning:  Cannot send session cache limiter - headers already sent (output started at /usr/local/apache/htdocs/hordenew/horde/lib/Prefs.php:109) in /usr/local/apache/htdocs/hordenew/horde/lib/Prefs.php on line 109

When authentication is handled by Horde, there are no problems
Any ideas?

-- 
Jan Kuipers,
Systeembeheer Lauwers College