gpg: cannot open /dev/tty: Permission denied

[Randy Harmon]

I'm trying GnuPG, and I'm having some problems.  This is on a Debian
Linux 2.0.37 box.  It verifies signatures OK, but spits out the
message "cannot open /dev/tty: Permission denied".

It will not encrypt, producing the same error message:

    echo hi | gpg -e -r my-email-address

I do not see any answer - or question - for this in the archives,
after searching thoroughly.

Any thoughts welcomed.

Randy