High RX power warning on SFP?

I have Nexus throwing up high RX power warnings on an SFP port every 5 minutes or so. This is a single mode run, about 500 meters away.

Ethernet3/18 transceiver is present type is 1000base-LH name is FiberStore part number is SFP1G-LX-31 revision is A0 serial number is F175CO25721 nominal bitrate is 1300 MBit/sec Link length supported for 9/125um fiber is 10 km cisco id is 3 cisco extended id number is 4 SFP Detail Diagnostics Information (internal calibration) ---------------------------------------------------------------------------- Current Alarms Warnings Measurement High Low High Low 

---

 Temperature 30.23 C 100.00 C -50.00 C 85.00 C -40.00 C Voltage 3.34 V 3.79 V 2.80 V 3.46 V 3.13 V Current 15.00 mA 90.00 mA 0.00 mA 85.00 mA 0.00 mA Tx Power -5.91 dBm -1.50 dBm -10.50 dBm -3.00 dBm -9.03 dBm Rx Power -4.94 dBm + -3.00 dBm -26.98 dBm -5.00 dBm -23.97 dBm Transmit Fault Count = 0 ---------------------------------------------------------------------------- Note: ++ high-alarm; + high-warning; -- low-alarm; - low-warning 

No warnings on the remote side, but this is the transceiver info:

ITU Channel not available (Wavelength not available), Transceiver is internally calibrated. mA: milliamperes, dBm: decibels (milliwatts), NA or N/A: not applicable. ++ : high alarm, + : high warning, - : low warning, -- : low alarm. A2D readouts (if they differ), are reported in parentheses. The threshold values are calibrated. High Alarm High Warn Low Warn Low Alarm Temperature Threshold Threshold Threshold Threshold Port (Celsius) (Celsius) (Celsius) (Celsius) (Celsius) --------- ------------------ ---------- --------- --------- --------- Gi1/0/49 32.3 100.0 85.0 -40.0 -50.0 High Alarm High Warn Low Warn Low Alarm Voltage Threshold Threshold Threshold Threshold Port (Volts) (Volts) (Volts) (Volts) (Volts) --------- --------------- ---------- --------- --------- --------- Gi1/0/49 3.34 3.79 3.46 3.13 2.80 Optical High Alarm High Warn Low Warn Low Alarm Transmit Power Threshold Threshold Threshold Threshold Port (dBm) (dBm) (dBm) (dBm) (dBm) --------- ----------------- ---------- --------- --------- --------- Gi1/0/49 -6.3 -1.5 -3.0 -9.0 -10.5 Optical High Alarm High Warn Low Warn Low Alarm Receive Power Threshold Threshold Threshold Threshold Port (dBm) (dBm) (dBm) (dBm) (dBm) ------- ----------------- ---------- --------- --------- --------- Gi1/0/49 -5.2 -3.0 -5.0 -24.0 -26.0 

I've replaced SFP's on both sides with no luck, what should I try next? I was going to try replacing the patch cables tomorrow.