I've now experienced two crashes with 5.4-RELEASE-p1 as outlined below. They appear to be the similar to: http://thread.gmane.org/gmane.os.freebsd.stable/27608 This is a Dell 2600 dual-xeon with HT disabled, running off of the Dell(AMR) Raid. It has a very mild load with Apache, Postgres, and Qmail. backtrace: http://redirx.com/?3b28 dmesg: http://redirx.com/?3b2r I had a similar problem after 5.3, but it was stable after disabling ACPI and I didn't pursue it further. It was previously 100% stable under 5.2/5.2.1. Dell Diagnostics as well as Memtest have been run extensively and no problems were found. I've never made claims as to my programming skills, but it seems there should be a fixable problem hiding here. I'm hunting for the cables to set up a serial console, but what's the next step? This is new territory for me. What other information can I provide? Thanks for any assistance. Mitch Parks