Through WWW it became clear the fault should lie in the fstab; located in ~/etc/fstab , that was indeed totally screwed up.
Important commands in this field:
sudo fdisk -l
ls /dev/disk/by-uuid -alh
Compare the results with the fstab file that you can open with sudo gedit /etc/fstab when you're in the root. This already solved a lot of problems but still it didn't work.
Finally I found the error the defaults options was listed before the filesystem description (ext3) in stead of after... Also I had to recreate the home folder in the right partition (another one as the root partition). So first delete it in root and sudo mkdir /home
and then sudo mount /dev/sda7 /home
The only good thing about all this misery was that I was able to solve it, but damn I 'm gonne deinstall Partition Magic.