PowerEdge SC440 - Memory Specs

I have tried 2 types of Corsair memory but both give error messages and computer will not launch into system setup/post. Bios will not allow change to any memory settings. I understand SC 440 can use either ECC or Non - ECC memory but not mixed. Any suggestions why this memory is not recognized?

 

CORSAIR XMS2 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model TWIN2X2048-6400C5DHX

 

http://www.corsair.com/_datasheets/TWIN2X2048-6400C5DHX.pdf

 

and

 

CORSAIR XMS2 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model TWIN2X2048-6400

 

 

http://www.corsair.com/_datasheets/TWIN2X2048-6400.pdf

 

Computer Specs