JRuby Installed with rbenv does not add my gem lib directories to the load path -

i installed jruby 1.7.4 using rbenv. i've installed several gems using gem install gemname shell jruby-1.7.4 set active ruby-- confirmed after installation gems in fact present in ~/.rbenv/versions/jruby-1.7.4/lib/ruby/gems/shared/gems. but, when try require of installed gems jruby, error. inspection shows lib directories not on $load_path. shouldn't lib dirs in gem directories specified above automatically there? if not, how them show there?