[horde] Authentication issues

[Steven Swarts]

G'day guys,

I have a Debian system with Horde 5.1.2 (latest PEAR) and ISPConfig 3 
installed.
Just recently I tried to log in with another user (mine (admin) works 
fine) and apache error log shows "user not authenticated..." plus the 
screen goes white, nothing shown, no error or what not just white.
I checked my authentication (after the log in expired - otherwise no 
refresh helps or clearing browser cache, etc) and its set to:

$conf[auth][driver] - Let a Horde application handle authentication
$conf[auth][params][app] - IMP

Now what I always thought was that it would authenticate based on the 
email, but can someone please explain this to me and hopefully help me 
out here?

*/Regards,/*

*/Steven Swarts/*