Rake doc:rails aborts due to denied permission

Hi,
I issue the following commands:

rails new dummy_app
cd dummy_app
rake doc:rails

When issuing the last command I notice that rake aborts due to denied
permissions. See below.

rm -r doc/api
Parsing sources
100% [485/485]
/opt/local/lib/ruby/gems/1.8/gems/railties-3.1.3/lib/rails.rb

Generating Darkfish format into
/Users/punjabdapunk/Projects/Ruby/dummy_app/doc/api
rake aborted!
error generating
/opt/local/lib/ruby/gems/1_8/gems/actionmailer-3_1_3/MIT-LICENSE.html:
Permission denied
/opt/local/lib/ruby/gems/1_8/gems/actionmailer-3_1_3/MIT-LICENSE.html
(Errno::EACCES)

Tasks: TOP => doc:rails => doc/api/index.html
(See full trace by running task withtrace)

Performing ls -la
/opt/local/lib/ruby/gems/1_8/gems/actionmailer-3_1_3/MIT-LICENSE.html
produces:

-rw-r–r-- 1 root admin 92997 27 Nov 23:17
/opt/local/lib/ruby/gems/1_8/gems/actionmailer-3_1_3/MIT-LICENSE.html

Is this normal behavior? Ive googled and searched forums but to no
avail.

Im a noob to all this and am willing to do what is needed to grok this.
Can someone point me in the right direction.

(on Mac OS X 10.6)

Thanks
Shazad