First thing to look at is if the devices are configured properly to send syslogs to ciscoworks.
If yes, check Syslog.log (win) or syslog_info (sol/lin) to see if the missing devices syslog appears in that file. If the syslog is present in file, check filters if the filters are configured properly to forward the syslog to syslog DB else they might be dropped.
Attached image explains the Ciscoworks Syslog Architechture properly.
-Thanks
Vinod
-Thanks
Vinod
**Rating Encourages contributors, and its really free. **