As of this writing, I've got it working (I think). Not sure exactly what the deal was, but I can tell you the things I did:
0) Called Lenovo support. This one was a mistake. The tech tried to update everything in System Update simultaneously. When I stopped him, he agreed to only update the Ricoh driver and the bios, plus resetting all the bios settings to defaults. This caused my computer to bluescreen on every bootup - even Safe Mode was inaccessible. After an hour of him trying to fix his mess, I hung up and started working on it myself. The issue turned out to be that Windows was attempting to re-install the graphics driver (and a bunch of other ones) on boot for some reason. I'm pretty sure the graphics driver was what was BSOD'ing me. I did a System Restore to roll back the drivers. This got me my Safe Mode back. Then I went into Safe Mode, uninstalled all the devices it was trying to update, uninstalled the graphics driver & updated it by hand, rebooted... Back to where I started - everything working but the card reader.
1) Removed all "Ricoh" packages from Control Panel / Uninstall Software.
2) Installed the latest from this page: http://www-307.ibm.com/pc/support/site. ... MIGR-73713
...which I think is the same thing that System Update will give you if you run it.
3) At this point I had a Ricoh SD/MMC Controller in Device Manager / IDE ATA ATAPI Controllers, as well as a SDA Standard Compliant SD Host Controller under SD host adapters, and probably some other stuff.
4) This is the confusing one. I had to turn off AHCI in my bios (set it to "Compatibility" mode, it's under Settings / SATA, or something like that). I don't know why this is the case, since I previously had it working with AHCI turned on. But there you have it. Didn't have to flip the AHCI bit in the registry, just turned it off in bios. Card reader now works.