Problem: The RAM you purchased is PC2-5300. (DDR2-667). The fastest memory the system can support is PC2-4200 (DDR2-533). Basically, the RAM is too powerful for the system. You need to purchase PC2-4200 or lower. (look for 533MHz).
I suggest:GSkill 2x1 PC2-4200
GSkill makes nice RAM and it happens to be the cheapest 2x1 PC2-4200 kit available on newegg.