Difficult upgrade

Hello, all. I wish I had more specific data to report but I've just had a very problematic upgrade on Debian Squeeze although it also has a number of packages installed from Wheezy. I'm not even sure which Trinity I was running beforehand - 12 or 13. I do know that, after the upgrade, I could not boot into a GUI - automatically or manually. For some reason, important packages were missing, viz., kdm-trinity, ksmserver-trinity, network-manager-kde-trinity, and a pile of their dependencies. The base Trinity packages were installed. Very strange but very painful. Again, I wish I had more specific details to report. Sorry - John