Comment 5 for bug 484429

The problem is only partially solved by making "Disk Utility" close the luks device.

In fact all other situations in which a device is not closed correctly also lead to this error.
I use an encrypted external harddrive. Whenever I shutdown the drive before unmounting or suspend the pc, then disconnect the drive and resume the pc, the luks device is not closed cleanly. Such situations can happen and should be handeled correctly, by making nautilus (or the gvfs backend, I'm not an expert here) close a luks drive automatically, when it is no longer accessible.

Steps to reproduce:
1) mount an luks-encrypted external harddrive
2) suspend the system
3) disconnect the drive
4) resume the system
5) connect the drive
6) try to mount the encryptet partition (happens automatically by default when inserted)

I would be happy to give further details when helpful and will test a patch if available.