[horde] Error when installing Horde webmail 1.2.3

[fastandfurious at numericable.fr]

Hello
here my regular error when I install Horde webmail 1.2.3 on my fedora 9 
:with pHp5.3.0

*Deprecated*: Assigning the return value of new by reference is 
deprecated in */usr/local/apache/htdocs/horde/pear/Log.php* on line *169*

*Deprecated*: Assigning the return value of new by reference is 
deprecated in 
*/usr/local/apache/htdocs/horde/lib/Horde/Notification.php* on line *64*

*Deprecated*: Assigning the return value of new by reference is 
deprecated in */usr/local/apache/htdocs/horde/lib/Horde/Perms.php* on 
line *455*

*Deprecated*: Assigning the return value of new by reference is 
deprecated in */usr/local/apache/htdocs/horde/lib/Horde/Perms.php* on 
line *462*

*Deprecated*: Assigning the return value of new by reference is 
deprecated in */usr/local/apache/htdocs/horde/lib/Horde/Perms/sql.php* 
on line *83*

*Deprecated*: Assigning the return value of new by reference is 
deprecated in */usr/local/apache/htdocs/horde/lib/Horde/Perms/sql.php* 
on line *116*

*Deprecated*: Assigning the return value of new by reference is 
deprecated in */usr/local/apache/htdocs/horde/lib/Horde/Perms/sql.php* 
on line *151*

*Deprecated*: Assigning the return value of new by reference is 
deprecated in */usr/local/apache/htdocs/horde/lib/Horde/Prefs.php* on 
line *847*

*Warning*: Cannot modify header information - headers already sent by 
(output started at /usr/local/apache/htdocs/horde/pear/Log.php:169) in 
*/usr/local/apache/htdocs/horde/index.php* on line *97

Could you help me please?
I found no reference on the horde site on this problem

best regards
***