Symptom:
-From SEL logs in UCS-M:

38d | 09/27/2013 11:49:46 | CIMC | Platform alert LED_BLADE_STATUS #0xba | LED color is green | Asserted 
38e | 09/27/2013 14:05:35 | CIMC | Voltage P0V75_DDR3_T6GP1 #0x15 | Lower critical - going low | Asserted | Reading 0.64 <= Threshold 0.64 Volts 
38f | 09/27/2013 14:05:36 | CIMC | Platform alert LED_BLADE_STATUS #0xba | LED color is amber | Asserted 
390 | 09/27/2013 14:05:40 | CIMC | Voltage P0V75_DDR3_T6GP1 #0x15 | Lower critical - going low | Deasserted | Reading 0.66 >= Threshold 0.64 Volts 
391 | 09/27/2013 14:05:40 | CIMC | Platform alert LED_BLADE_STATUS #0xba | LED color is green | Asserted 
392 | 09/27/2013 15:17:16 | CIMC | Voltage P0V75_DDR3_T6GP1 #0x15 | Lower critical - going low | Asserted | Reading 0.64 <= Threshold 0.64 Volts

-Meanwhile IPMI reports all OK:
P0V75_DDR3_T1GP1 | 0.660   | Volts        | OK     | 0.601   | 0.640   | na      | na      | 0.708   | 0.747   | 
P0V75_DDR3_T2GP1 | 0.660   | Volts        | OK     | 0.601   | 0.640   | na      | na      | 0.708   | 0.747   | 
P0V75_DDR3_T3GP1 | 0.650   | Volts        | OK     | 0.601   | 0.640   | na      | na      | 0.708   | 0.747   | 
P0V75_DDR3_T4GP1 | 0.660   | Volts        | OK     | 0.601   | 0.640   | na      | na      | 0.708   | 0.747   | 
P0V75_DDR3_T5GP1 | 0.650   | Volts        | OK     | 0.601   | 0.640   | na      | na      | 0.708   | 0.747   | 
P0V75_DDR3_T6GP1 | 0.660   | Volts        | OK     | 0.601   | 0.640   | na      | na      | 0.708   | 0.747   | 
P0V75_DDR3_T7GP1 | 0.679   | Volts        | OK     | 0.601   | 0.640   | na      | na      | 0.708   | 0.747   | 
P0V75_DDR3_T8GP1 | 0.650   | Volts        | OK     | 0.601   | 0.640   | na      | na      | 0.708   | 0.747   | 
P0V75_DDR3_T1GP2 | 0.669   | Volts        | OK     | 0.601   | 0.640   | na      | na      | 0.708   | 0.747   | 
P0V75_DDR3_T2GP2 | 0.660   | Volts        | OK     | 0.601   | 0.640   | na      | na      | 0.708   | 0.747   | 
P0V75_DDR3_T3GP2 | 0.660   | Volts        | OK     | 0.601   | 0.640   | na      | na      | 0.708   | 0.747   | 
P0V75_DDR3_T4GP2 | 0.660   | Volts        | OK     | 0.601   | 0.640   | na      | na      | 0.708   | 0.747   | 
P0V75_DDR3_T5GP2 | 0.660   | Volts        | OK     | 0.601   | 0.640   | na      | na      | 0.708   | 0.747   | 
P0V75_DDR3_T6GP2 | 0.660   | Volts        | OK     | 0.601   | 0.640   | na      | na      | 0.708   | 0.747   | 
P0V75_DDR3_T7GP2 | 0.660   | Volts        | OK     | 0.601   | 0.640   | na      | na      | 0.708   | 0.747   | 
P0V75_DDR3_T8GP2 | 0.669   | Volts        | OK     | 0.601   | 0.640   | na      | na      | 0.708   | 0.747   |

-Checking  CIMC IPMI collection via dplug on blade confirms fluctuations:
1da | 10/21/2013 04:07:38 | CIMC | Voltage P0V75_DDR3_T6GP1 #0x15 | Lower critical - going low | Asserted | Reading 0.64 <= Threshold 0.64 Volts 
1db | 10/21/2013 04:07:38 | CIMC | Platform alert LED_BLADE_STATUS #0xba | LED color is amber | Asserted 
1dc | 10/21/2013 04:07:42 | CIMC | Voltage P0V75_DDR3_T6GP1 #0x15 | Lower critical - going low | Deasserted | Reading 0.67 >= Threshold 0.64 Volts 
1dd | 10/21/2013 04:07:43 | CIMC | Platform alert LED_BLADE_STATUS #0xba | LED color is green | Asserted 
1de | 10/21/2013 04:58:49 | CIMC | Voltage P0V75_DDR3_T6GP1 #0x15 | Lower critical - going low | Asserted | Reading 0.64 <= Threshold 0.64 Volts

Conditions:
Working blade, not reported 'inoperable' but SEL continuously filled with voltage alerts.