[horde] Error after upgrading from RC2 to FINAL

[Juan C. Blanco]

Hello, I've just upgraded from the RC2 to FINAL version of Horde 4.0 and 
IMP 5.0

After the upgrade In the Traditional mode I can not see icons of the 
message flags in the message list and whenever I delete or restore a 
meesage I get this error in the Apache log file and in the browser

[Thu Apr 07 22:38:38 2011] [error] [client XXX.XXX.XXX.XXX] PHP Fatal 
error:  Call to a member function get() on a non-object in 
/usr/share/php5/PEAR/Horde/Imap/Client/Socket.php on line 2931, referer: 
http://XXX.fi.upm.es/horde/imp/

Retrying the web page shows the message succesfully deleted or restored 
but without the icon flags

In the Dynamic Mode I can see the icons of the message flags, but 
whenever I delete or restore a message I receive an alertthat shows 
"Error when communicating with the server"

Regards
Juan C. Blanco