Question: Optimum Settings for Blitz Formula Mobo and 4x1GB Ballistix PC2-8500 Memory

Could someone please help me set my memory to the optimum settings on this motherboard.

Having spoke to Crucial today, they said that the Blitz Fomula can not run at 1066 with 4x1GB sticks.

They did say that I should be running the memory on 4-4-4-12. Could someone please explain what this setting gives me over the default 5-5-5-15.

Motherboard: Blitz Formula
Memory: 4x1GB Ballistix 2x1GB DDR2 PC2-8500, 5-5-5-15, UNBUFFERED, NON-ECC
(the ones with the yellow heatsink)

TIA