This same issue is still a current problem even after removing all but the necessary kext from EXTRA. SATA0 responds normally (maybe a little slower than normal)... while SATA 1-5 sometimes don't even appear on desktop as usable drive. Again this is my Dell T3400 with X48 chipset, 8gig ram, QX9650, ICH9R which still is not recognized by system profiler. I'm gonna put my money on a problem with dsdt.asl not working properly.
I don't see any errors in console that relate to these disk access issues.

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Gigabyte GA-EP45-DS3L • OS X 10.6.3 Retail thru BootCD • QX6600@2,6GHz • 8GB Kingston 666MHz • PNY GeForce 8600GTX • AsereBNL 1.1.9 • BlackOSX 01/17 dsdt.aml • LegacyHDA

Asus Rampage Extreme x48 • OS X 10.6.3 Retail thru BootCD • HAF 932 • PSU Corsair HX-1000W • QX9770 @ 4.1ghz • 4GB OCZ 3P20002G @ 1800mhz • EVGA GTX-285 • Boot 2x VR 300GB RAID0 ICH9

Dell T3400 • 10.6.3 • x38 • QX6750 • 8gb • 9800GT • Voodoo HDA • Netgear GA-311