Hi Frank
I have the same problem and also in Nexus 5596.
With following configuration, the event will dissapear:
sw-n1k# conf t
sw-n1k(config)# logging level radius 2
sw-n1k#
2013 Sep 13 13:51:15.190 sw-cpd-n1k-1 %RADIUS-3-RADIUS_ERROR_MESSAGE: setsockopt success, Using src-intf: for sock 30. Error: Success
2013 Sep 13 13:59:01.481 sw-cpd-n1k-1 last message repeated 2 times
2013 Sep 13 13:59:01.481 sw-cpd-n1k-1 %VSHD-5-VSHD_SYSLOG_CONFIG_I: Configured from vty by <...> on x.x.x.x@pts/19
2013 Sep 13 13:59:09.608 sw-cpd-n1k-1 %SYSMGR-STANDBY-5-CFGWRITE_STARTED: Configuration copy started (PID 28395).
sw-n1k#
Regards.