debian boot problem on sun ultra 60

[Guy Thomas <gt@fks.be>]

I installed sarge on a sun ultra 60 (450Mhz) using tftpboot (the sun 
having no cd drive). First I used a 2.4 boot image, next a 2.6 boot 
image. Both installations went fine.

However, when the machine was rebooted after the installation, I got the 
following error when I used the 2.6 boot image:
"Fast Instruction Access MMU Miss"

When I used the 2.4 image, I got a similar error:
"Fast Data Access MMU Miss". In fact, in this case the boot procedure 
just hangs and I get the message when I press Stop+A.

I already went through a couple of mailing lists, but to no avail.

Anybody any idea what goes wrong or how to solve this?

Thanks