I've justudpated to version 8.165. The email I got said that the system was up for 1 day and 20 hours. However, the system reboot after the update
I have provided the relevant logs:
2011:05:31-17:25:41 ***** auisys[29962]: Installing up2date package file '/var/up2date//sys/u2d-sys-8.164-165.tgz.gpg'
...
2011:05:31-17:27:36 ***** auisys[29962]: Initiating reboot
Thanks