Debian :: Installation Doesn't Work

I'm trying to install Debian 5.0x to my miniITX computer.

Setup:

I had this setup running in a previous configuration. The only difference were the disks. I had a 120GB and a 1TB (/home). Because I need more space I swapped both disks for 2 x 2TB.

I tried a 64bit Debian 5.xx stable install. Everything goes fine until the first boot. After the POST and BIOS screen a cursor justs blinks and the computer does nothing. the computer doesn't start GRUB

Well I thought maybe a small error with downloading the DVD so I tried another debian but Testing now. There the setup hangs when it wants to make the file-systems. It says something like can't make ext4 filesystem. I also tried with ext3. So I manually tried to do fdisk and mkfs.ext4 (and mkfs.ext3) for both disks in the console during installation. fdisk works but when I try mkfs.ext4 /dev/sda1 it says that some bin-file is missing? How's that possible on an installation disc? Never ever had that before?

Well after 15 attempts (meanwhile lost 2kg of fingernails)I tried another 32 bit DVD install of Debian 5.xx. It can make the filesystems again and install everything but when it has to boot for the first time it just doesn't. I don't even see GRUB.

Seems to me that the computer doesn't refer to the HD to boot. In the BIOS the BOOT order is just fine (the previous config with the old HD's just worked fine). Even when I put in the install DVD it skips the HD and boots from the DVD?

I really don't get it. The disks are both shown in the BIOS. Is this a hardware or software issue? I think that Linux or GRUB should be able to work with 2TB discs isn't it?