Thank you for really trying to help me out on this instead of booing a newbie (and I did search all forums before posting this thread).
Well, I have done exactly as you suggest, and also made sure, that all repos now are for the chinook. But, unfortunately, problem unchanged. I try to install, download comes through, but then "Unable to install xxx". Have tried with about 10 programs. The only ones appearing in the "Installed programs" list are Map and osso-xterm.