Symptom:
On a Nexus 5000 switch, false transceiver warnings are seen in the syslog.

%ETHPORT-4-IF_SFP_WARNING: Interface Ethernet1/1, High Temperature Warning
%ETHPORT-4-IF_SFP_WARNING: Interface Ethernet1/1, Low Temperature Warning
%ETHPORT-4-IF_SFP_WARNING: Interface Ethernet1/1, High Tx Power Warning
%ETHPORT-4-IF_SFP_WARNING: Interface Ethernet1/1, Low Tx Power Warning
%ETHPORT-4-IF_SFP_WARNING: Interface Ethernet1/1, High Rx Power Warning
%ETHPORT-4-IF_SFP_WARNING: Interface Ethernet1/1, Low Rx Power Warning
%ETHPORT-4-IF_SFP_WARNING: Interface Ethernet1/1, High Current Warning
%ETHPORT-4-IF_SFP_WARNING: Interface Ethernet1/1, Low Current Warning

%ETHPORT-4-IF_SFP_WARNING: Interface Ethernet1/1, High Temperature Warning cleared
%ETHPORT-4-IF_SFP_WARNING: Interface Ethernet1/1, Low Temperature Warning cleared
%ETHPORT-4-IF_SFP_WARNING: Interface Ethernet1/1, High Tx Power Warning cleared
%ETHPORT-4-IF_SFP_WARNING: Interface Ethernet1/1, Low Tx Power Warning cleared
%ETHPORT-4-IF_SFP_WARNING: Interface Ethernet1/1, High Rx Power Warning cleared
%ETHPORT-4-IF_SFP_WARNING: Interface Ethernet1/1, Low Rx Power Warning cleared
%ETHPORT-4-IF_SFP_WARNING: Interface Ethernet1/1, High Current Warning cleared
%ETHPORT-4-IF_SFP_WARNING: Interface Ethernet1/1, Low Current Warning cleared

Conditions:
Nexus 5000 switch is running NX-OS 5.2(1)N1(5) and both High and Low warnings are seen for the same test. E.g. Temperature, TX Power, RX Power, Current.