Hi ! I´m having the same issue with my external Samsung SATA / USB HDD. I´ve installed the iDeneb 10.5.7 in my computer, so I updated via Combo Update to the version 10.5.8 but I had a Kernel Panic ... so i brought back my old extensions and the system is working fine now, but since then, my External HDD doesn´t work anymore. The same HDD works perfectly in my Macbook, so I know the hardware is ok. I think that´s some kext who´s nos working fine. If someone could help us, we would be very grateful! Thanks!