Got some more juicy troubleshooting info on this problem. I installed Ubuntu 10.04.3 LTS on another system and configured the OpenPGP smartcard settings. It is working properly for my non-root user account. Naturally I wanted to check out the permissions on the usb device.
Under my normal account I first ran a
gpg --card-edit to tie up the usb card reader device, then I ran
sudo lsof -c gpg | grep usb to find the device file. This yielded noting so I ran
sudo gpg --card-edit and got an error message!
seth@swk:~$ sudo gpg --card-edit
[sudo] password for seth:
gpg: WARNING: unsafe ownership on configuration file `/home/seth/.gnupg/gpg.conf'
gpg: detected reader `SCM SCR 3310 00 00'
gpg: pcsc_connect failed: sharing violation (0x8010000b)
gpg: apdu_send_simple(0) failed: locking failed
Please insert the card and hit return or enter 'c' to cancel: c
gpg: selecting openpgp failed: general error
gpg: OpenPGP card not available: general error
Something else was tying up the usb card reader. Let's find out what:
sudo lsof | grep usb
This yielded the nugget I was looking for.
pcscd 2362 root 5u CHR 189,4 0t0 2194 /dev/bus/usb/001/005
So apparently the pcscd service grabs the card reader device on behalf of the non-root user and relays gpg read/write requests to the card on a properly configured OpenPGP setup.
Let's take a look at the permissions of the device file.
seth@swk:~$ ls -l /dev/bus/usb/001/005
crw-rw-r-- 1 root root 189, 4 2011-10-18 11:49 /dev/bus/usb/001/005
OK, now I think I'm getting closer. On the 11.10 system I remember the group was set to pcscd and not root. It looks like the problem might be with the pcscd package. I'll try configuring an 11.10 system with the same permissions and report back.
UPDATE: So I set the user and group permissions on the usb device of a fresh 11.10 Ocelot install to root and root. The command
gpg --card-status still fails as non-root user. I'm guessing that this is a bug in the pcscd package for now.