Hi,
 
  The syslog-ng don't log any alert of snort.
   I'm using syslog-ng-1.5.17 and the configuration file syslog-ng.conf.sample tha come with it.
   The syslog is loging all snort alerts without problem.
   I'm using snort with -s option and LOG_ATHPRIV and LOG_ALERT in configuration file
 
Tks