Installing Ubuntu 12.04 from USB-stick to the second disk (/dev/sdb) was running fine until reboot. Grub stops with a "no such device" message and a rescue prompt:
grub rescue> ls
No second harddisk recognized by grub. Only /dev/sda with the Win-XT partition is found. Is there any way to tell grub explicitly that there is a second harddisk and how to find it? This second disk is a CF-card mounted with an adapter as secondary SSD inside of an Asus EeePC 901. The first disk is the 4GB onboard SSD. Due to BIOS indication these two are working as secondary master and slave. Even resizing the Win-XT partition to put the /boot directory on the recognized disk /dev/sda (with complete reinstall) doesn't change anything.