The Facts:

[Johannes Zarl]

Hi,

On Saturday 15 November 2014 11:52:02 david at gbenet.com wrote:
> Laptop-1 and laptop-2 are a mirror image of each. They contain the same
> software. I copied programmes like Thunderbird Firefox from laptop-1 to
> laptop-2 without any problems.

It seems like the mirroring of laptop-1 to laptop-2 did not actually work as 
expected:

> (1) david at laptop-1:~$ gpg
> gpg: directory `/home/david/.gnupg' created
> gpg: new configuration file `/home/david/.gnupg/gpg.conf' created
> gpg: WARNING: options in `/home/david/.gnupg/gpg.conf' are not yet active
> during this run gpg: keyring `/home/david/.gnupg/secring.gpg' created
> gpg: keyring `/home/david/.gnupg/pubring.gpg' created
> gpg: Go ahead and type your message ...

The above command output tells you that no .gnupg folder exists in your home 
directory and that a new one is created. As some people pointed out before, 
you have to copy the .gnupg folder from your laptop-1 to your laptop-2.

Maybe you forgot to restore your home directory when you migrated from 
laptop-1 to laptop-2?

Cheers,
  Johannes