Comment 9 for bug 1293058

Since the error is occurring when trying to read a non-Ubuntu-provided library, my guess is that the file /lib/security/pam_usb.so is not installed with the correct privileges. I would suggest either removing your user-built packages and installing the equivalent Ubuntu packages (libpam-usb) or else grant the manuallyy installed library the correct permissions (chmod a+r /lib/security/pam_usb.so).

Please try one of the above and see if that solves the problem.