I have a ThinkPad whose cardbus sockets used to work, maybe a year ago.
I haven't noticed them in months, because the machine's mostly
self-sufficient, but I tried to put in a USB controller, and it didn't work.

Tracking it down, I find:

cbb0 at pci2 dev 0 function 0: vendor 0x1180 product 0x0476 (rev. 0xa8)
cbb0: can't map socket base address 0x50000000
pci_io_find: expected type i/o, found mem
cbb0: can't map socket base address 0x1: io mode
cbb1 at pci2 dev 0 function 1: vendor 0x1180 product 0x0476 (rev. 0xa8)
cbb1: can't map socket base address 0x50100000
pci_io_find: expected type i/o, found mem
cbb1: can't map socket base address 0x1: io mode
cbb0: bad Vcc request. sock_ctrl 0xffffff88, sock_status 0xffffffff
cbb0: disabling socket
new status 0xffffffff
cbb0: interrupting at irq 11
cardslot0 at cbb0 slot 0 flags 0
cardbus0 at cardslot0: bus 3 device 0
pcmcia0 at cardslot0
cbb1: bad Vcc request. sock_ctrl 0xffffff88, sock_status 0xffffffff
cbb1: disabling socket
new status 0xffffffff
cbb1: interrupting at irq 11
cardslot1 at cbb1 slot 1 flags 0
cardbus1 at cardslot1: bus 6 device 0
pcmcia1 at cardslot1

This is, as suggested, a Ricoh 476 chip.  I am not sure whether the
all-f's sock_status is a warning sign, or what to make of the pci_io_find
messages.  I don't have relevant dmesg output... Oh, wait, I do!

cbb0 at pci2 dev 0 function 0: vendor 0x1180 product 0x0476 (rev. 0xa8)
cbb1 at pci2 dev 0 function 1: vendor 0x1180 product 0x0476 (rev. 0xa8)
cbb0: interrupting at irq 11
cardslot0 at cbb0 slot 0 flags 0
cbb1: interrupting at irq 11
cardslot1 at cbb1 slot 1 flags 0

This is what it looked like on October 11, 2004.

One of the few changes since then which could possibly matter is that the
machine went from 1GB to 2GB of memory, but I don't *think* that should
matter.

-s