Since upgrading to SL I've been having major problems with my Apple RAID card. After the upgrade the system crashed a few times (kernel panic) within a few days. (I don't have the messages anymore but it did appear to be RAID related) Each time it crashed the system came up and did not see the RAID card at all. When I rebooted the machine again the RAID card was there and the volumes needed to reinitialize. This happened about three times. This morning the RAID utility said that disk one had failed. I tried rebooting the machine thinking it was similar to my previous problems and on reboot the machine just hangs (at the grey startup screen) no apple logo, nothing. I can't boot from CD, I can't boot from any of the non-RAID volumes on my machine, can't boot from external drives (I can't even get the Apple Hardware Test to run) If I remove the RAID card the machine starts up fine. Was there an EFI update with SL? Could the SL upgrade be causing all of these problems or did my RAID card just happen to die at the same time? Any help / suggestions would be much appreciated.