[CentOS] gpg encryption problem

Whenever I try to use gpg to encrypt a single file on CentOS 4.2, I get the below error:

/root/.gnupg/.#lk0x56a998.localhost.localdomain.19548': No such file or directory gpg: keyblock resource `/root/.gnupg/secring.gpg': general error gpg: failed to create temporary file `/root/.gnupg/.#lk0x56aca8.localhost.localdomain.19548': No such file or directory gpg: keyblock resource `/root/.gnupg/pubring.gpg': general error gpg: no default secret key: secret key not available gpg: /home/ra/Desktop/zoo001.jpg: sign+encrypt failed: secret key not available

It happens for normal and root users.

Does anyone know what I am doing wrong? I've tried "gpg -e [filename]" and numerous other flags...

thanks