[imp] [IMP] Login twice (horde and imp) only first time

[Arminas]

Hello,

I know it is very frequently asked question, but my problem is a
little bit different. I have to log in twice if user connects to horde
system first time. So here is the scenario:

1. wellcome screen
2. login ok, but have to login another time (to imp). There is a
sidebar visible on the left, but on another frame it is asked to enter
username and password.
3. login ok. user can read his mail.

but after such scenario, when log of, the step 2 is skipped so user
logs in once..

I'm using:
* Horde: 3.1.6
* Imp: H3 (4.1.6)
* Ingo: H3 (1.1.5)
* Turba: H3 (2.1.7)

BR,
Arminas