when running portupgrade triggering reboot / how to do detailedsystem log to see precise reboot trigger?

[rtjohan at syspres.com]

Have not been able to keep machine up-to-date with cvsup since each time 
after the cvsup has completed, the portupgrade reboots the machine.

Probably the first thing to do is to enable some log utility to capture 
what triggered the reboot.
How should I go about this - logging in as much detail to figure what 
happened?

Running FreeBSD 5.1 Release with KDE.

The applications/libraries are all up-to-date except for the list below. 
Seems obvious that upgrading one of those packages triggered the reboot. 
Here are the pieces that are out-of-date from cvsup:
    - arts
    - cdparanoia
    - cups-base
    - esound
    - gconf2
    - gnome-icon-theme
    - gnomevfs2
    - kdemultimedia
    - libbonobo
    - libbonoboui
    - libgnome
    - libgnomeui
    - linux_base
    - p5-Net
    - pcre
    - pilot-link
    - scrollkeeper