Strange reboot since 9.1

[Loïc Blot]

Hello,
Since FreeBSD 9.1 I have strange problems with the distribution. Some
servers are rebooting without any kernel panic, instanly. First i
thought it's a problem with my KVM system, but one of my FreeBSD under a
Dell R210 have the same problem.
The servers concerned are now:
- Monitoring server
- LDAP test server
- Some other servers, randomly (not in production).
First i thought it's a problem with my FreeBSD install, then i download
another time the ISO but the problem was already here. After i try
another thing, install 9.0 and upgrade to 9.1 but same problem.
How can i get informations about this problem ?

Thanks for advance.
-- 
Best regards, 

Loïc BLOT, Engineering
UNIX Systems, Security and Networks
http://www.unix-experience.fr