It looks like that is the default config for kiwi so you're not filtering anything, I don't think the problem is there.
Try changing the logging level to debugging to see if you get anything.
Also try these commands...
config terminal
archive
log config
logging enable
Any configuration changes you make should then show up as syslogs making it easier to test (and why wouldn't you want config changes logged somewhere anyway right?).
The only other questions I have would be...
Are the switch and syslog server on the same subnet? If not, it could be a routing issue or firewall issue.
