Major problems installing Trinity 3.5.13 with Slavek's repository on Fresh install of Squeeze

I have frequently installed Trinity before, 3.5.11, 3.5.12, 3.5.13, 3.5.13 with Slavek's repositories. I have never had a problem before. I am getting desperate. I am running 3.5.10 on Lenny on my working m/c at the moment, and the system is sickly. I *need* a working box. And I *need* KMail in order to have continued access to my emails. I have been trying for hours over several days to install on a newbuild. I have posted before about the problems I had initially. When I installed desktop-base-trinity separately it went on without a hitch. I can find no way of installing kde-trinity. Having tried for hours to install kde-trinity from where I had got to, I gave in and installed LXDE. I immediately gained a functioning LXDE. I have installed from inside LXDE frequently in the past. I have installed with Slavek's repositories already enabled in the past. Having got my functioning LXDE, I again tried to install kde-trinity. Again no success. Exactly the same result as before. I installed some of the missing packages manually, but most of them refused to install. I have just tried again, and this time I got a shorter, and therefore legible, list of problems, but most of the unresolved dependencies were virtual packages and refused to install. The only thing that I can think of to try now is to do a default install of Squeeze, get Gnome 3 (yuk!) and try to install from there. Any better ideas? All suggestions welcomed. Lisi