Hi Hughe.

     Here is my own experience with installing Debian as from several 
releases back:

     I always partition by hand but, if I do it naively, partition 1, 
5,6,... starting from the beginning of the disk, grub always fail to 
install with no understandable message.

     I proved to myself that the reason was the lack of room at the 
begining of the disk to install grub itself.

     What I do now is to reserve some free space at the beginning of the 
disk, like a few sectors - I don't care even sacrifying a cylinder if 
there are plenty. It may be possible to use parted for that, but it is a 
CLI, and I'm not very comfortable with it; I prefer cfdisk which is a 
CUI (curses user interface).

     There's a step in the installation process where the installer asks 
the user if xhe wants some additional packages. I ask for cfdisk. Later, 
when it comes to partitionning, I escape the installer by ctrl-alt-f1 
and run cfdisk.

     To preserve a sensible ordering of partition numbers, and since 
cfdisk does not provide a simple way to reserve a free space, I proceed 
as follows:
     1) create partition 1 at the end of the disk - size doesn't matter 
I'll destroy it soon
     2) create partition 2 at the beginning, with the size I want to 
give to the free space
     3) delete partition 1 and re-create it with the size I really need, 
at the beginning, that is on top of partition 2
     4) delete partition 2

     I have now three regions: a small free space, partition 1, and a 
big free space. Now I can populate the big free space and leave the 
small one unused for Grub to install. Then I return to the installer 
with ctrl-alt-f7; at the end, Grub is installed without problem.

     Didier