Random reboots

My Fortigate WIFI 60B, latest build (v4.0,build0291,100824 (MR2 Patch 2)) is randomly rebooting. I can' t see a cause for it other than this little blurb in the Event Log. 317 2010-10-30 17:49:00 information dhcp 26001 Client requests IP address/configuration parameters 318 2010-10-30 17:49:00 information system 20001 authentication Client 00:23:12:0b:2d:6b does WPA 319 2010-10-30 17:49:00 information system 20001 associate Accepted association from 00:23:12:0b:2d:6b 320 2010-10-30 17:48:55 information admin 32006 Fortigate started 321 2010-10-30 17:48:55 notice admin 32401 init add Administrator daemon_admin added an application control list WoW-Choke from init 322 2010-10-30 17:48:55 notice admin 32401 init add Administrator daemon_admin added an application control list monitor-p2p-and-media from init 323 2010-10-30 17:48:55 notice admin 32401 init add Administrator daemon_admin added an application control list block-p2p from init 324 2010-10-30 17:48:55 notice admin 32401 init add Administrator daemon_admin added an application control list monitor-all from init 325 2010-10-30 17:48:55 notice admin 32120 init add Administrator daemon_admin added an address all from init