Why can't I sign an RPM package with my GPG key?

[KevinDrums]

I build my package: 'rpmbuild -ba SPECS/rmmr.spec' and this results in a source and noarch package.
I can check the
'rpm --checksig RPMS/noarch/rmmr-1.8-1_3kc.noarch.rpm SRPMS/rmmr-1.8-1_3kc.src.rpm'
RPMS/noarch/rmmr-1.8-1_3kc.noarch.rpm: sha1 md5 OK
SRPMS/rmmr-1.8-1_3kc.src.rpm: sha1 md5 OK

I want to add my GPG signature to the packages and try this:
rpm -v --addsign SRPMS/rmmr-1.8-1_3kc.src.rpm
rpm: SRPMS/rmmr-1.8-1_3kc.src.rpm: No such file or directory

But, 'ls -l SRPMS/rmmr-1.8-1_3kc.src.rpm' reports
-rw-r-----. 1 kevinc kevinc 7547 Apr 15 11:24 SRPMS/rmmr-1.8-1_3kc.src.rpm

I've been signing packages just fine since the mid 1990s with RPM 4.0. Now on Fedora 16 I can't sign packages? I added '-v' to rpm to report what's going on. But, that didn't help. I'm guessing that there's some temporary directory somewhere that doesn't exist. But, I can't figure out what's going on.

Any ideas people?

Thanks....