[horde] [Horde 5.2.5+dovecot+pgsql+debian7+apache2] PDO object don't work‏

[Aramir Galanodonel]

Hello,

First of all, it's my first time installing it so I might have done something wrong.

So
 I recently installed Horde, but I can't get it to work correctly, 
whenever I try to add a user (using SQL backend) this error pop up:
http://pastebin.com/ZuyNhY6T

In fact it seems to happen every time something requires a PDO objects (when I check up the locks, access personal data, etc)

The
 weird thing is, I can log out, and log back in using the admin account.
 So horde can access to the database.... at least sometimes.

Any help or hint would be appreciated.
Thanks for reading.