Yep build the binary rpm packages from the samba.org source: http://samba.org
One needs to use the redhat/fedora spec file and copy some files after extracting/installing the src.rpm file.
This stuff gets used, you have to unpack the samba-3.0.25c.tar.bz2 to have access to them;
The files in the /SOURCES/samba-3.0.25c/packaging/RHEL/setup files replaces the setup.tar.bz2 in the /SOURCE directory. One has to create the file tar.bz2 file from this dirctory, hint: right-click on the directory
The file in the SOURCES/samba-3.0.25c/packaging/RHEL/samba.spec directory replaces the /SPECS/samba.spec file.
When done type from the /SPECS directory location: rpmbuild -ba samba.spec
The rpm-build package needs to be installed for this to work. Depending on how you build the rpm packages (as root or otherwise) the /SPECS and /SOURCES locations could be;
(as root) /usr/src/redhat
(as non-root) /home/<username here>/rpmbuild
One also needs to rebuild the kernel and add back the missing smbfs support.