Rails,RSpec,Rcov,Lib

Okay, I've probably just been staring at this for too long, but here is
the problem I hope to get some help with:

I'm creating a little lib directly inside rails for integrating with
Plesk. I'm also creating two custom rake tasks to get test and coverage
results just on the plesk stuff. Problem is, I can't see to find the
right combination to get just the plesk files run with rcov. This is
what i have so far:

Spec::Rake::SpecTask.new('spec:plesk:rcov') do |t|
  files = Dir.glob('spec/lib/plesk/**/*_spec.rb')
  files << 'spec/lib/plesk_spec.rb'
  t.spec_files = files
  t.rcov_opts << %w{--include-file lib\/plesk\/,lib\/plesk.rb}
  t.rcov_opts << %w{--rails --exclude app\/,spec\/,lib\/}
  t.rcov = true
end

Right now, I get all the lib/plesk stuff (including lib/plesk.rb, but I
also get all the spec/lib/plesk stuff (including spec/lib/plesk.rb).

Can anyone give me just a little nudge in the right direction? How do I
get rid of the spec files from coverage?