Problem : Apache2 is not runing

[Fredspace]

Hello Everybody.
I ve got a problem with apache2 since i ve update my Plesk from 9.0.3 to 9.5.4.
since this update, every sunday between 01h20 & 01h25 UTC, the apache process stop and i need to restart it manually. (with the command line in ssh or by the plesk web admin).
In /etc/var/log/user.log i ve got this message :
Dec 2 01:20:01 vds3-31 CHECK_APACHE2: Apache2 is running
Dec 2 01:21:29 vds3-31 syslogd 1.4.1#18: restart.
Dec 2 01:25:01 vds3-31 CHECK_APACHE2: Apache2 is not running.
Dec 2 01:25:01 vds3-31 CHECK_APACHE2: Start Daemon Apache2
Dec 2 01:25:01 vds3-31 CHECK_APACHE2: /etc/init.d/apache2 start
Dec 2 01:30:01 vds3-31 CHECK_APACHE2: Apache2 is not running.


and in /var/log/apache2/error.log.1 :
[Sun Dec 02 01:21:19 2012] [notice] caught SIGTERM, shutting down


Any idea to solve this problem ?

Thanks a lot
Kind regards

Fredspace