facter

undefined method get_uptime for Facter::Util::Uptime:Module (NoMethodError)

I'm trying to setup a puppet node, but rubygems doesn't seem to behave. If I run facter on the cli via it's own binary (/usr/lib/ruby/gems/1.8/gems/facter-1.5.8/bin/facter), it works fine, but if I run it through the binary installed by rubygems (/usr/bin/facter), it throws: /usr/lib/ruby/1.8/facter/uptime.rb:11: undefined method `get_...