emerge -u world fails due to single dependency check

[devi0s]

I've been trying to update world for quite some time now to no avail.

When I type

emerge -up world
or
emerge -up evolution

a mozilla dependency

>=app-crypt/gnupg-1.2.1

fails and claims that all builds to satisfy

>=app-crypt/gnupg-1.2.1

are masked. I have manually and successfully emerged gnupg-1.2.1 as well as gnupg-1.2.1-r1 to no avail and continue to receive the same error regardless of which version happens to be installed. An

emerge -s gnupg

shows that gnupg-1.2.1 is indeed installed.

grep -i gnupg /usr/portage/profiles/package.mask

does not yield any results, so I am unable to explicitly unmask gnupg here by editing the file, as has been suggested to me in the #gentoo irc channel.

So I have a few questions:

1) What may be the cause of the problem?
2) How do I fix it?

AND

3) Why does

emerge -up --deep world

fail instead of continuing and successfully upgrading those packages not affected by the phantom masked gnupg so I can at least have a mostly up-to-date system?

4) Flamebait, but relevant: Why would anyone want to use Gentoo when a package-specific error prevents an upgrade of the rest of your system?

I appreciate any help the list can offer a struggling new Gentoo user; Thank you all in advance for your help.

[sebgarden]

Try to comment out the ACCEPT_KEYWORD line in make.conf or pass it as a parameter with