Hi Jhon
This is a manifestation of a known bug in 5.x release. This is not deemed to be service impacting and so, no SMU planned for this on 5.3.4. Fix requires code to be upgraded. Bug reference is CSCva77939
Considering upgrading for this problem is not worth the time/efforts. If it is annoying, please consider implementing the following, as a workaround:
! Event Correlator
logging suppress rule SNMP-SENSOR alarm PLATFORM ENVMON OPERATION_FAIL
logging suppress apply rule SNMP-SENSOR all-of-router
! SNMP view exclude
snmp-server view sensor iso included
snmp-server view sensor 1.3.6.1.4.1.9.9.91 excluded
snmp-server community xxxxx view sensor RO
! Message suppressed
RP/0/RSP0/CPU0:xxx(config)#logging suppress rule SNMP-SENSOR alarm PLATFORM ENVMON OPERATION_FAIL
RP/0/RSP0/CPU0:xxx(config)#logging suppress apply rule SNMP-SENSOR all-of-router
RP/0/RSP0/CPU0:xxx(config)#commit
Doing so can potentially hide genuine alarms from sensors. So, please decide judiciously and proceed forward.
I hope this helps ... Palani