IMP 3.0 doesn't work

[Mimmus]

Hi list,
I successfully used CVS versions of Horde/IMP/Turba until now but, after
infamous PHP security bug, I thought to upgrade the whole environment to the
'stable' versions.
Mail server is Exchange 5.5 with IMAP enabled.
I made a fresh install of horde-2.0.tar.gz and imp-3.0.tar.gz.

I untarred Horde under webserver root (/var/www/html) and made minimal
configuration, according to config/INSTALL doc and using MySQL to store
preferences.
http://mywebserver/horde/test.php gives good output.
Same thing for IMP.

After login, I got a page with a 'Welcome, myname@mydomain.it' banner and an
'INBOX 0' link.
If I click on this link (or on the Mail link in the footer), I see the usual
messages list. I'd like to enter directly in this page.

In addition, I'm unable to avoid 'Initial folder' textbox in the login form.

Thanks for any support.
Domenico Viggiani