Well, I follow your advices. I re-flashed the n800, even downloaded a new image (3 hours). But the problems persist. The only installed programs are map and osso-xterm. I added the repositories from http://gronmayer.com/it/, and deleted the ones not for chinook. Try to add programs, ie pidgin, it downloads, but then "Cannot install Pidgin". There is no option for informing on details. I tried with 4 other programs, same problem. I guess I will have to reflash with my 2007 image or wait for the final OS2008 - or?

Heureka!
I had given up and decide to go back to OS2007, but then tried something different first: flashed in R&D mode wit OS2008, became root and installed with apt-get - and then, installed Pidgin, Mirage AND Skype with no problems, all works flawlessly -
But thanks everybody anyway - jensjk