Sebastian,
Try logging in as root and run 'fidk -l'. This will tell you which partitions are on your disks.
My partition layout looks like this:
~# fdisk -l
Disk /dev/hda: 255 heads, 63 sectors, 3737 cylinders
Units = cylinders of 16065 * 512 bytes
Device Boot Start End Blocks Id System
/dev/hda1 * 1 13 104391 83 Linux
/dev/hda2 14 46 265072+ 82 Linux swap
/dev/hda3 47 3737 29647957+ 83 Linux
/dev/hda1 is the /boot (like yours), and /dev/hda3 is the / disk.
Hope this helps,
Kai