freebsd 8.2 on amd64 opteron

[David Collins]

Hi List,

I have been using FreeBSD for a number of years and love it. I have a
friend who is competent it linux and wanted me to help him get started
with BSD. 

He has an amd64 opteron dual core 2GHz w/ 4G memory. Not realising we
installed the i386 version of freebsd 8.0 and upgraded to 8.2 without
any problem. We then tried the amd64 version of 8.2 which installed
without any problems. However, when we log in the system either
reboots or panics with a message on the screen within about 10
minutes. 

I have googled around and not found very much information about this.
Does anyone have any ideas that I can try to overcome this?

Thanks

David Collins