[imp] Cannot login with IMP 3.1

[Thomas Booms]

Hello,

i want to login in IMP 3.1, but cannot. Under IMP 3.0 it's running.

Please help me to fix this. Thanks in advance.

My configuration is the following:
Horde Versions
Horde: 2.1
IMP: 3.0 (run IMP tests)
Turba: 1.1
Kronolith: 1.0
Nag: 1.0
Mnemo: 1.0
Imp-neu: 0 (run Imp-neu tests) [This is 3.1, but not working, and i will 
remove it soon]
PHP Version
View phpinfo() screen
PHP Version: 4.2.0
PHP Major Version: 4.2
PHP Minor Version: 0
PHP Version Classification: release
You are running a supported version of PHP.
PHP Module Capabilities
FTP Support: Yes
Gettext Support: Yes
IMAP Support: Yes
LDAP Support: Yes
MCAL Support: Yes
Mcrypt Support: Yes
MySQL Support: Yes
PostgreSQL Support: No
XML Support: Yes
Miscellaneous PHP Settings
magic_quotes_runtime set to Off: Yes
PHP Sessions
Session counter: 1
To unregister the session: click here
PEAR
PEAR - Yes
Recent PEAR - Yes
Mail::RFC822 - Yes
Log - Yes
DB - Yes