Comment 21 for bug 148003

I have fixed this problem by REMOVING /etc/udev/rules.d/65-dmsetup.rules. Now there are no stale devices, the password dialog appears every time I insert the stick, and the volume is auto-mounted reliably.

Fedora (7) does not have any analogous file and does not have any problems with LUKS-encrypted USB devices.

cryptsetup (libdevmapper) creates the nodes in /dev/mapper itself. If you let udev do it there is a potential for nasty race conditions (see e.g. https://wiki.ubuntu.com/UdevDeviceMapper).

You may want to check this file (it appears as debian/dmsetup.udev in the source) to see if the symlinks are still needed, but I'm pretty sure that you should not be using NAME="mapper/$env{DM_NAME}" because it conflicts with libdevmapper.