Random lockups on 3ware 8506-8

I've been experiencing random lockups on a few of our servers with a
3ware 8506 SATA controller.  Sometimes during the middle of the night,
or early in the morning.  The machine basically freezes and has to be
power cycled.  No keyboard, errors on the console, nothing to say what
the problem was.

I found a PR that seems to follow the same pattern as my problems: PR kern/70360

(http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/70360)

However, haven't seen anything else.

Anybody else experiencing the same symptoms?

Thanks.