I am currently using a Intel DG41TX motherboard. It throws a beep code for memory error with the Q6600, but boots to the OS fine with a E4400. I have no idea why it is not working.
There's really not enough information here to determine anything. The Q6600 is a higher TDP processor. What is the power supply that you are attempting this with?
Do you have the latest available BIOS installed? If not, use the E4400 to install the latest and then try again.
Did you purchase this processor new (in a sealed box) or used?