The only thing I am seeing that could be wrong is the 4gb RDIMM that we sell and support for this server is 2Rx8 instead of 2Rx4 that you have installed. Dell's servers are very sensitive to its memory configurations. Here is the part number and details:
C1KCN 4GB DIMM, 1333MHz, 2RX8X72, 8K, 240, Regulatory
The only other 4GB dual ranked RDIMM is low voltage:
9J5WF 4GB DIMM, 1333MHz, 2RX8, 8K, 240, Regulatory, Low Voltage
Regards,