I'll let you in on an amusing secret- it's the same isp driver in FreeBSD
as it is in NetBSD- at least the core parts are the same. The difference
here may be in how CAM configures things, or the isp_netbsd part of the
equation, but it also may be that using the SRM loaded f/w works better
here.

Pick up

	ftp://ftp.feral.com/pub/outgoing/netbsd.gz

which is an ALPHA netbsd kernel (from sources about a day or so old)
with the option ISP_DISABLE_FW added and see if that helps.

-matt