installation issue 6.2 AMD64-bit 3ware 9550SX

[Jon Langton]

I am trying to install FreeBSD-stable 6.2 64-bit from
CDROM and the installation hangs. The installation
hangs after the 3ware 9000 Series Storage Controller
is recognized (using the twa0 driver). If I disable
ACPI, I get to the sysinstall screen, however, no
hard drives are detected.

Here is a list of the system details

(2) AMD Opteron 2210 processors
    Super Micro HDa8-2 Motherboard
    3ware 9550SX-12 SATA RAID Controller
(8) Seagate 7200.10 750 Gb SATA hard drives
    GeForce 7300GS PCI-E video card
    Sony DVD/CDROM
    Sony AIT4 tape drive
    nVidia Corp MCP55 ethernet