Your board requires non-ecc memory: See section 1.5 on page 18 of http://downloadmirror.intel.com/15192/eng/D915GUX_TechProdSpec.pdf
or Intel® Desktop Board D915GUX — System memory
The memory you have is ecc memory: http://www.kingston.com/dataSheets/KVR400D2S4R3_2G.pdf
Doc