via686b corruption back

Hello,

I have been having strange data corruption related problems for some time.
I spent some time this weekend
trying to track down the issues.

My system: Asus A7V-E, Bios 1004, Athlon 1.2, running a 40G HDD off the
first IDE controller in UDMA/100.

Symptons: Writing large files (first discovered with corrupt ISO images) to
the local HDD causes
corruption.  I can reliably corrupt the files with a simple test of:

	md5 ISO-IMAGES/* &
	cp ISO-IMAGES/* test ; md5 test/*

After much disk thrashing the contents of the ISO images in the test
directory are corrupt.

The symptoms seemed to start some time around 4.7.  

I have booted a few kernels over the last day to try and check this out:
1) linux-2.4.18 works fine
2) windows 2k works fine
3) freebsd-4.6.2 works fine
4) freebsd-4.7-stable no good
5) freebsd-5.0p7 no good
6) freebsd current from 12th April no good.

I have never seen a dmesg output saying the the corruption bug was being
fixed at boot time either.

Any ideas?

Regards/mark