[horde] Horde stopped working after update distro update - keep getting login screen

[horde at ceefar.co.uk]

Hi all,
 
I hope someone can help me with this.  I recently upgrade my Ubuntu 6.06 to
Ubuntu 8.04 and everything was fine with that however Horde has stopped
working.  The initial issue was due to IMAP not being reinstalled which I
have done, but now when I try to log in, I get the login screen again if the
credentials are correct and an address in the address bar which ends:
horde/imp/login.php?url=%2Fhorde%2Fservices%2Fmaintenance.php%3Fdomaintenanc
e%3D1%26amp%3Bmodule%3Dimp
 
I have checked the test.php and everything looks as it should, the session
counter increases on a refresh.  I am now a bit baffled.  I might have been
able to work it out if I could check the logs however it appears the logs
are no longer being updated either since ubuntu was updated so I have no
idea what is happening now.
 
Any help is much appreciated.
 
Thanks
 
Casey