Hi Yellowbeard,
Follow up: The 4GB 1333 kit (PC3-10600 TW3X4G1333C9DHX) booted up at 1066 (1:2 with the 1066 FSB CPU) and works just fine. The voltage can be adjusted with the DX mobos (booted at 1.5v) but for running at 1066 1.5v is stable so I left everything at defaults.
Vista-64 is a happy bunny
