So, finally my download finished. The upgrade from tde(squeeze) to tde(wheezy) almost wenf flawless. There was just one issue:
# apt-get dist-upgrade The following packages have unmet dependencies: kdeartwork-trinity : Depends: kdeartwork-theme-icon-trinity (>= 4:3.5.13-2debian0~pre10+4~wheezy) but 4:3.5.13-1debian0+ax1~squeeze is installed
# apt-get -f install
Took a while, but no further errors occured.
What's left from tde(squeeze):
# apt-show-versions |grep squeeze libcaldav 4:14.0.0-0debian11+r4+pr2~squeeze newer than version in archive libcarddav 4:14.0.0-0debian11+r4+pr2~squeeze newer than version in archive
These I had to gowngrade manually (synaptic, as I don't know the correct command line options :-) )
Now I strart testing, but it looks very good right now. My former errors did not reappear.
Nik