GPG error

["stephen_b_allen@tiscali.co.uk" <stephen_b_allen@tiscali.co.uk>]

Just today, my normal working build now fails. It falls over installing 
Opera.
I have been installing it by adding opera_10.00.4585.gcc4.qt3_i386.deb 
in the /config/chroot_local-packages.
It has all worked previously, if I remove the deb file then the build 
is successful.

This is the error I get:
=======================================================
W: GPG error: http://deb.opera.com stable release;
The following signatures could'nt be verified because the public key 
is not available: NO_PUBKEY <number>
=======================================================
a few lines on I get:

=======================================================
WARNING: The following packages could not be authenticated
opera
E: There are problems and -y was used without --force-yes

=======================================================

Next, (after finding that from a booted debian-live build & apt-get 
update "opera" is listed ) I added opera to my packlist and now get 
this error:
 =======================================================
Package opear is not available, but is refered by another package. 
This may mean that the package is missin, has been obsoleted or is only 
available from another source.
=======================================================

Plesae help, I'm  stuck . Do I need to add to my --categories.

Thanks




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