rails disables gems from loading previous versions on 1.9

from
http://groups.google.com/group/rubyonrails-core/browse_thread/threa...

if you install the "test-unit" gem v1.2.3 and 2.0.6,

then try to load v1.2.3

ex, this action:

def go

gem 'test-unit', '= 1.2.3'
require 'test/unit/version'
render :text => Test::Unit::VERSION

end

it should render '1.2.3', but it instead render '2.0.6' (with ruby 1.9)

reason: within the line "gem 'test-unit', '= 1.2.3'", gems searches for the @gem_prelude_index within the $:, can't find it (because active_support accidentally cleared it when it did a $LOAD_PATH.uniq!)

I...think this is unexpected.
Thanks.
-r ref:
http://rubyforge.org/tracker/index.php?func=detail&aid=27699&am...