This one is puzzling me. I have a Dell Latitude e4200. The SD card reader is detected and the driver is loaded:
$ sudo lspci -v
02:01.1 SD Host controller: Ricoh Co Ltd R5C822 SD/SDIO/MMC/MS/MSPro Host Adapter (rev 22) (prog-if 01)
Subsystem: Dell Device 0277
Flags: bus master, medium devsel, latency 64, IRQ 18
Memory at f65ff600 (32-bit, non-prefetchable) [size=256]
Capabilities:  Power Management version 2
Kernel driver in use: sdhci-pci
Kernel modules: sdhci-pci
No matter what SD card I insert into the slot, absolutely nothing is detected. DMESG, syslog, all completely empty of anything when the card is inserted.
$sudo lsmod | grep sdhci
sdhci_pci 13989 0
sdhci 27387 1 sdhci_pci
Ubuntu 11.04, btw.