pinentry stdin problems

[S3]

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I recently upgraded from GPG v1.4 to GPG v2.
Previously, I was able to do this:
tar c | gpg -s > a.tar.gpg

However, with the new version that uses pinentry,
it does not allow me to insert my password
whenever I redirect stdin as above.  I don't
even get the ncurses password entry box.

Is there a way to make this work as before?
Can pinentry be made to fallback to the plain text
password entry, should the other ones fail?

- --
echo 'scale=49861;sqrt(7)' | BC_LINE_LENGTH=81 bc -l \
  | tail -n 1 | tr '0-9' 'eeniSg tlr'
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Version: GnuPG v2.0.7 (GNU/Linux)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iD8DBQFHuItwxzVgPqtIcfsRAoXBAJ4i+i/Ne3+W8IqLnV0GCbQQuJmC9gCfUYW0
chlLNEhB5CK9M5ecLJzxch4=
=Z3gc
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