apt-get purge does nothing

[Sergio Callegari]

On natty.

To reproduce

1) Set up things so that you have a package that is not installed, but for which configuration data is still present on the system
(not installed with residual config in synaptic).

2) at the prompt type
sudo apt-get purge <package>
or
sudo apt-get --purge remove <package>

What happens:

You see something like the following

sudo apt-get remove --purge grub
[sudo] password for callegar:
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
  grub*
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.

And the package is not purged

What should happen

You should see something like

sudo apt-get remove --purge grub
[sudo] password for callegar:
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
  grub*
0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded.
Do you want to continue (y/n)?

And by saying yes you should have the package purged