Problem installing FreeBSD 4.8

[Wayne Pascoe]

Hi all,

I've got a problem installing FreeBSD 4.8 on my new toy. I've tried
installing from cdrom and from floppy, and I get the same error.

During the boot process, all seems to be going well until
plip0: <PLIP network interface> on ppbus0
but then I get
acd0: MODE_SENSE_BIG command timeout - resetting
ata0: resetting devices .. done
over and over again. I've let it run for 20 minutes and it doesn't stop. 

The machine is a dual Xeon 2.4Ghz with 2GB ram. The motherboard appears
to be a Tyan S2721-533 Thunder i7501 Pro. The only addon card is the
Mylex Megaraid controller.

Any ideas on getting this to boot so that I can install ? :(

-- 
Wayne Pascoe