allthough I configured --with-pam --with-pam_smbpass the subdir is not being compiled and thus results in a very small and unusable /lib/security/pam_smbpass.so. occured first on 3.0.25 and ist still present in 3.0.25a. Copying pam_smbpass.so from 3.0.24 built helps.
*** This bug has been marked as a duplicate of 4657 ***