Fedora Core 6 won't install on Dell Optiplex 320 (SB600 SATA AHCI unrecognized)

Howdy.

I've been trying to install Fedora Core 6 on a brand new Optiplex 320 (BIOS 1.0.9) and Fedora can't find the hard disk.

It appears related to the ATI SB600 SATA controller.

Here is a portion of the dmesg logs:

...
7>ahci 0000:00:12.0: version 2.0
6>ACPI: PCI Interrupt 0000:00:12.0 -> GSI 22 (level, low) -> IRQ 209
6>ahci 0000:00:12.0: AHCI 0001.0100 32 slots 4 ports 3 Gbps 0xf impl IDE mode
6>ahci 0000:00:12.0: flags: 64bit ncq ilck pm led clo pmp pio slum part
6>ata1: SATA max UDMA/133 cmd 0xDE8F6D00 ctl 0x0 bmdma 0x0 irq 225
6>ata2: SATA max UDMA/133 cmd 0xDE8F6D80 ctl 0x0 bmdma 0x0 irq 225
6>ata3: SATA max UDMA/133 cmd 0xDE8F6E00 ctl 0x0 bmdma 0x0 irq 225
6>ata4: SATA max UDMA/133 cmd 0xDE8F6E80 ctl 0x0 bmdma 0x0 irq 225
6>scsi0 : ahci
6>ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
4>irq 192, desc: c06dee00, depth: 1, count: 0, unhandled: 0
4>->handle_irq(): 00000000, _stext+0x3fbffd40/0x3c
4>->chip(): c0674820, 0xc0674820
4>->action(): 00000000
4> IRQ_DISABLED set
4> IRQ_WAITING set
4>unexpected IRQ trap at vector c0
4>ata1.00: qc timeout (cmd 0xec)
4>ata1.00: failed to IDENTIFY (I/O error, err_mask=0x104)
6>ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
4>ata1.00: qc timeout (cmd 0xec)
4>ata1.00: failed to IDENTIFY (I/O error, err_mask=0x104)
6>ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
4>ata1.00: qc timeout (cmd 0xec)
4>ata1.00: failed to IDENTIFY (I/O error, err_mask=0x104)
6>ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
6>scsi1 : ahci
6>ata2: SATA link down (SStatus 0 SControl 300)
6>scsi2 : ahci
6>ata3: SATA link down (SStatus 0 SControl 300)
6>scsi3 : ahci
6>ata4: SATA link down (SStatus 0 SControl 300)
...

I've seen some posts about using a legacy IDE mode for this particular SATA chipset, but I'm not sure if there is a command line option to enable this mode in the kernel.

I've verified that 1.0.9 is the latest BIOS and I don't see any BIOS options that would let me put this into a legacy/IDE mode.

I've tried Knoppix version V4.0.2 and it doesn't find the disk either.

Any suggestions?

Thanks!