PulledPork 0.4.2 501 error when downloading rules

This issue most typically stems from a missing Perl Module that is required to communicate via SSL using LWP::Simple.  This required Perl Module is Crypt::SSLeay and is not included in the LWP::Simple redistributed package from the Ubuntu 8.x repositories, and will typically fail to install via CPAN on many Ubuntu server installations.  As such you simply need to do the following (on Ubuntu, since this is the only place I have seen it broken):

sudo apt-get install libcrypt-ssleay-perl

Of course if you are not running Ubuntu then you will need to use CPAN or find whatever repackaged garbage that your distro is using to distribute this ;-).

One other cause could be that your root certificates are outdated, so if you have the aforementioned PM installed and are still receiving a 501.. this is likely the cause... google how to update your root certificates for your distro!  Again, for the sake of completeness, this is how you do it on Ubuntu:

sudo apt-get install ca-certificates
sudo update-ca-certificates

I have also added this to the PP FAQ.

Cheers,
JJC