[imp] newmail popup problem after upgrade

[alois.blasbichler@sb-brixen.it]

Hello list

We upgraded from:
Horde: 3.0.10  Imp: H3 (4.0.4) Ingo: H3 (1.0.2) Kronolith: H3 (2.0.6)
Passwd: H3 (3.0) Turba: H3 (2.0.5)
to:
Horde: 3.1.3  Imp: H3 (4.1.3) Ingo: H3 (1.0.2) Kronolith: H3 (2.1.2)
Passwd: H3 (3.0) Turba: H3 (2.1.2)

Now i have the problem that the popup-message that a new mail is
comming dont appear. Seems a problem with the old preference settings
of old users.
Because, wenn i create a new user ore i delete all preferences of a old
user the popup works fine.
With a old user (having/or not  nav_popup=1 in the preferences) the  
popup dont work

Wath can i do to solve?
For preferences we use a Postgres-DB.
The user are stored in ldap (Openldap on Linux)

Thnak you
luis