Thanks chemist!

But even after more than one week later there is still no approach to a solution.
Even the authors of the HAZE son't show up.

Okay, it is even worse the N900 cannot support ICQ and MSN natively.

How can we proceed further? Using pidgin is no solution so far.

EDIT
It seem I've fixed it. I had different errors, so here my solutions: Followed up every single thread and tried a few things:

Update from 0.8 to 0.9 was broken:

1. Deinstalled Extra-Plugins via apt-get remove --purge libpurple0 and something more... is weeks ago, so I have to look what I've done exactly -if someone needs it!
2. Deaktivacted Extras-Testing and Extras-Devel.
3. Installed Extra Plugins v0.7 out of Repo Extras via programmanager
4. apt-get update
   apt-get upgrade
   > installed 0.9 without problems

Login-Problem. Hitting the "login" resulted in nothing.

1. With 0.8 downgrade to 0.7!
2. updated 0.7 to 0.9
3. removed client-login and ssl
4. Port 5190 (?)

Contacts didn't show up

1. installed 0.9
2. RESTARTED the phone
3. Logged in, all contacts where shown

> Merged with Contacts-Merger. :-)

German people can follow up here: Maemo-Experts.info