I found your node when researching Net::SFTP. I hope this post may help other people in the future if they do the same.

I just installed Net::SFTP on a "This is perl, v5.6.1 built for i686-linux-thread-multi" machine, and I wrote down the order in which the modules were reported missing by CPANPLUS.

It was surprisingly straight-forward considering the mess it was to get it running on Windows (a PPM with Net::SSH::w32Perl saved the day IIRC).

 Test::More
  Math::GMP
   String::CRC32
  Net::SSH::Perl
  Class::Loader
      Convert::ASCII::Armour
      Crypt::CBC
      Crypt::Primes
       Crypt::Blowfish
      Tie::EncryptedHash
      Sort::Versions
      Data::Buffer
     Digest::BubbleBabble
    Crypt::RSA
   Crypt::DES
   Crypt::DSA
  Math::Pari (y get GP/Pari  ftp://megrez.math.u-bordeaux.fr/pub/pari/
+unix/)
   Crypt::Random
  Crypt::DH
   Crypt::DES_EDE3
   Convert::ASN1
  Convert::PEM
 Net::SSH::Perl 
     (both SSH2 and SSH1, 3DES) 
     (Only SSH will fail a test. I wrote a note about this on the bug 
+tracking site)
Net::SFTP
[download]

I'll install this on another Linux machine, and also a Solaris machine, and try to refine the list if I encounter any other problems.

/J