ULTRA66/DMA mode 4 in Linux?

PhiberOptik asks: "I recently got a BP6 board, with onboard ULTRA66 controllers and ran into a problem with my Red Hat 6.0 installation. It seems that Red Hat Linux will not support the controllers, which my main hard disks are hooked up to. So far as I know, no Linux distros exist with ULTRA66 support, and BeOS or Solaris 7 won't recognize them either. Are there any updates or distros which support this new technology?"