install messages/errors

[Pete Nicol <nicol_(_at_)_vrl_(_dot_)_com_(_dot_)_au>]

Whilst trying to install obsd from ftp, the following (typical) errors
constantly occur during the ftp process.  Prior to this, install goes
fine. 

wdo: (pciide0:0:0): timeout
	type: ata
	c_bcount: 65536
	c_skip: 0
pciide0:0:0: Bus-Master DMA error: missing interrupt, status=0x21
wd0d: DMA error writing fsbs 21168 of 21168-21183 (wd0 bn 283248; cs 281
tn 0 sn 0) retrying
wd0: soft error (corrected)

v strange ... works for a while, then after a while stalls on 'retrying'
and never gets to 'soft error (corrected)'

I have tweaked my bios as far as I can, to no avail.

Disk is a Western Digital 'Caviar 2850', 1654cylinders, 16heads, 853.6MB

I have two of these and the error occurs on both machines.

Box runs windows and linux fine.

I am unsure how to proceed, or even if this is a drive, bios or mobo
problem.

If anyone has seen this before, or has any advice on how to complete the
installation, it would be much appreciated.