[horde] Passwd : undefined index "admins"

[Arnold]

Dear Sir:

I have vpopmail, Horde, IMP, Turba, passwd with vpoppassword (from
poppass-ceti-1.8-3mdk.i586.rpm) in Mandrake 9 and Horde and Turba wiht
MySQL.

All seems to work fine, but when i try to change one user password i get
this message:

  Notice: Undefined index: admins in
/var/www/html/horde/passwd/templates/main.inc on line 23

  Warning: Wrong datatype for second argument in call to in_array in
/var/www/html/horde/passwd/templates/main.inc on line 23

What should i do to fix this??

Thank you VERY much.
This Horde-IMP-Turba is really amazing !!!