Hi champagne! Have to say that I really haven't had much trouble with kpackage. It is a bit weak as far as "what was the problem" exactly when installing a package fails, but in general it fetches the dependencies just fine for me. Where it also can be a pain is when I go "shopping spree" for several unrelated things, one of them will fail for whatever reason leaving the rest unconfigured in limbo. So I often have to fall back to command line with dpkg --configure -a to get the rest done. It may not be the most intuitive front end for apt but I love making a "shopping list" and ticking off things

I couldn't tell with Mustang whether he was having trouble with kpackage the application itself or apt in general due to like you noted, the mix of sources he has.

Mustang, whatever you try next, be sure to do apt-get update (not to be confused with upgrade) first, regardless of what frontend if any you are using. If you are using an old database, it would definitely cause problems similar to some of what you are seeing here