[Kroupware] many php errors in log

[d4rke1f at katamail.com]

In my apache-error.log I find a lot (like 2000 repeating lines) about a php error:

(this is a *small* excerpt)
[Mon Nov 17 10:02:49 2003] [error] PHP Notice:  Undefined index:  deleteflag in /kolab/var/kolab/www/admin/user/index.php on line 106
[Mon Nov 17 10:02:49 2003] [error] PHP Notice:  Undefined index:  deleteflag in /kolab/var/kolab/www/admin/user/index.php on line 106
[Mon Nov 17 10:02:49 2003] [error] PHP Notice:  Undefined index:  deleteflag in /kolab/var/kolab/www/admin/user/index.php on line 106
[Mon Nov 17 10:02:49 2003] [error] PHP Notice:  Undefined index:  deleteflag in /kolab/var/kolab/www/admin/user/index.php on line 106
[Mon Nov 17 10:02:49 2003] [error] PHP Notice:  Undefined index:  deleteflag in /kolab/var/kolab/www/admin/user/index.php on line 106
[Mon Nov 17 10:02:49 2003] [error] PHP Notice:  Undefined index:  deleteflag in /kolab/var/kolab/www/admin/user/index.php on line 106
[Mon Nov 17 10:02:49 2003] [error] PHP Notice:  Undefined index:  deleteflag in /kolab/var/kolab/www/admin/user/index.php on line 106
[Mon Nov 17 10:02:49 2003] [error] PHP Notice:  Undefined index:  deleteflag in /kolab/var/kolab/www/admin/user/index.php on line 106
[Mon Nov 17 10:02:49 2003] [error] PHP Notice:  Undefined index:  deleteflag in /kolab/var/kolab/www/admin/user/index.php on line 106
[Mon Nov 17 10:02:49 2003] [error] PHP Notice:  Undefined index:  deleteflag in /kolab/var/kolab/www/admin/user/index.php on line 106
[Mon Nov 17 10:02:49 2003] [error] PHP Notice:  Undefined index:  deleteflag in /kolab/var/kolab/www/admin/user/index.php on line 106
[Mon Nov 17 10:02:49 2003] [error] PHP Notice:  Undefined index:  deleteflag in /kolab/var/kolab/www/admin/user/index.php on line 106
[Mon Nov 17 10:02:49 2003] [error] PHP Notice:  Undefined index:  deleteflag in /kolab/var/kolab/www/admin/user/index.php on line 106
[Mon Nov 17 10:02:49 2003] [error] PHP Notice:  Undefined index:  deleteflag in /kolab/var/kolab/www/admin/user/index.php on line 106
[Mon Nov 17 10:02:49 2003] [error] PHP Notice:  Undefined index:  deleteflag in /kolab/var/kolab/www/admin/user/index.php on line 106
[Mon Nov 17 10:02:49 2003] [error] PHP Notice:  Undefined index:  deleteflag in /kolab/var/kolab/www/admin/user/index.php on line 106
[Mon Nov 17 10:02:49 2003] [error] PHP Notice:  Undefined index:  deleteflag in /kolab/var/kolab/www/admin/user/index.php on line 106

and so on...
What could this be?
Thanks in advance...