amd64 5.3rc1 panic during install on 8GB RAM Tyan S2885 w/ twe disk

[James R. Van Artsalen]

My Tyan S2885 K8W repeatedly panics during the file copy with CD install 
of 5.3rc1.

2x Operon 248, 8GB split between them (2 2GB DIMMs each CPU). 2 disk 
(mirrored arrays) under twe (3ware 8606-8).

This hardware configuration worked well under 5.2.1 for a couple of 
months.  I've reinstalled 5.2.1 and it still works fine there.

The system reboots before I can see what the message is, but there's 
something about "busdma" in there.