Again something strange: I get the system booting from CD-Rom if I modify the boot option with the SCSI-BIOS setup tools that ship with the controller. This just does not work as expected. Before I set the device ID which should be booted to the ID of the CD-Rom which did not work out. Now, just accidently, i set the ID to n+1 (ID of CD-Rom was 4 = n, so n+1=5) and it works. What's that - certainly a workaround :-) but nevertheless strange!
cheers ecky