rake path seems wrong

I'm trying to test rake to make sure it works but I'm getting the
following error

/usr/local/bin/rake:19:in `load': no such file to load --
/Users/mauro/.gem/ruby/1.8/gems/rake-0.8.7/bin/rake (LoadError)
  from /usr/local/bin/rake:19

rake is installed in /usr/local/bin/rake

not sure why the path is screwed up. How do I fix this???