Spamassassin and perl lib Net::DNS

I have installed and am running a local version of SA (3.1.0). The problem is that I would like to get the updated Net::DNS perl lib installed and so far have had no luck.

Using cpan there are several tests that fail. I can do a force install but I am curious why the tests fail in the first place. I also see errors on the install of the Mail::DomainKeys, Crypt::OpenSSL::Random and the Crypt::OpenSSL::RSA libs as well.

For those of you who have installed SA and the Net::DNS lib can you tell me if the test failures are normal? Should I go ahead and force the install or is there somethign that I am missing.