Try putting this in your kernel config:

options         PCIBIOS                 # PCI BIOS support
options         PCIBIOSVERBOSE          # PCI BIOS verbose info
options         PCIBIOS_ADDR_FIXUP      # fixup PCI I/O addresses
options         PCIBIOS_BUS_FIXUP       # fixup PCI bus numbering
options         PCIBIOS_INTR_FIXUP      # fixup PCI interrupt routing
options         PCIBIOS_IRQS_HINT=0x0a00 # PCI interrupts hint. IRQ 9 or 11
options         PCIBIOS_INTR_GUESS      # see pcibios(4)
options         PCIINTR_DEBUG           # super-verbose PCI interrupt fixup

I think you might need PCIBIOS and PCIBIOS_INTR_FIXUP.  I had similar
symptoms on a Thinkpad 600 (2645-41U), and the above got it working.
At least it should give you more debug info.

-- 
        Greg Troxel <gdt@ir.bbn.com>