[imp] Login after update not possible

[Mehmet]

Hi,

I have updated my Horde 3.1.4 to "Groupware Webmail Edition 1.2.3" on my
Server.
The problem is that I can't log in at the webmail site
(http://webmail.my-domain.de).
Sending and receiving emails with outlook works properly.
I don't get an error message. I get a refresh of the window with empty
fields (User and password) and nothing happens.
I'm sure that the email-adress and passwort are correct.
The logfile shows a correct login (.Login Success for.)!
When I switch back to my old installation everything works fine.
I'm running an Windows Server.
Here is a part of the test.php:
---------------------------------------------------------
Horde Version
    * Horde: 3.3.4
Horde Applications
    * Dimp: H3 (1.1.2)
    * Horde: 3.3.4
    * Imp: H3 (4.3.4) (run Imp tests)
    * Ingo: H3 (1.2.1) (run Ingo tests)
    * Kronolith: H3 (2.3.1) (run Kronolith tests)
    * Mimp: H3 (1.1.1)
    * Mnemo: H3 (2.2.1)
    * Nag: H3 (2.3.2)
    * Passwd: H3 (3.0) (run Passwd tests)
    * Turba: H3 (2.3.1) (run Turba tests)
PHP Version
    * View phpinfo() screen
    * View loaded extensions
    * PHP Version: 4.4.7
    * PHP Major Version: 4.4
    * PHP Minor Version: 7
    * PHP Version Classification: release
    * You are running a supported version of PHP.
---------------------------------------------------------
Thank you in advance for your advice!

regards,
Max