[syslog-ng] Syslog Blocked

[Tokie]

Hi For All,
i have a strange problem.
On my server syslog (on Debian Etch) I installed syslog-ng and some 
times syslog-ng don't works!!!
The programs is in execution, but don't receive the log in destination 
files;

Logrotate makes the new file (ex. /var/log/syslog/new) and compress the 
last with gz; this works!!
But the new file remains empty!!
If I restart the syslog-ng with /etc/init.d/syslog-ng restart(like below 
at Jan  5 17:56:34) , it begins to write on new file!!
This is my /var/log/messages
> Jan  4 06:25:21 s_all at sys-server.tokie syslog-ng[2690]: SIGHUP 
> received, reloading configuration;
> Jan  5 06:25:22 s_all at sys-server.tokie syslog-ng[2690]: SIGHUP 
> received, reloading configuration;
> Jan  5 17:56:34 s_all at sys-server.tokie syslog-ng[2690]: SIGTERM 
> received, terminating;
> Jan  5 17:56:34 s_all at sys-server.tokie syslog-ng[2690]: syslog-ng 
> shutting down; version='2.0.0'
> Jan  5 17:56:35 s_all at sys-server.tokie syslog-ng[3111]: syslog-ng 
> starting up; version='2.0.0'
Every day in cron should be restart syslog at 06:25
I think the problem is SIGHUP, but I don't know why!!
This don't happen every day, but randomly!!

Somebody can help me??

Tokie