Try downloading the rails 1.1.6 tgz from the rubyforge download page, extract the contents and copy the extracted vendor/rails directory to your project's RAILS_ROOT/vendor/ directory, this should overwrite the installed gem version with the rails version in your vendor directory (aka 1.1.6)
ie.
dir (or ls, etc) RAILS_ROOT/vendor/
(should result in)
.. rails/
.. plugins/
then: dir RAILS_ROOT/vendor/rails/ (should result in) .. actionmailer/ .. actionpack/ .. activerecord/ .. etc.
Ciao Gustav Paul