'rvm-auto-ruby' not picking up on 'rvm use' changes

gistfile1.sh

$ rvm --version

rvm 1.8.3 by Wayne E. Seguin ([email protected]) [https://rvm.beginrescueend.com/]

$ rvm use default
Using /Users/cczona/.rvm/gems/ruby-1.9.2-p290 with gemset global

$ rvm-auto-ruby --version
ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-darwin10.8.0]

$ rvm current
ruby-1.9.2-p290@global

$ rvm use 1.9.1
Using /Users/cczona/.rvm/gems/ruby-1.9.1-p431

$ rvm-auto-ruby --version
ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-darwin10.8.0]

$ rvm current
ruby-1.9.1-p431

$ rvm use 1.8.7
Using /Users/cczona/.rvm/gems/ruby-1.8.7-p352

$ rvm-auto-ruby --version
ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-darwin10.8.0]

$ rvm current
ruby-1.8.7-p352

$ rvm use system
Now using system ruby.

$ rvm-auto-ruby --version
ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-darwin10.8.0]

$ rvm current
system

$ ruby -v
ruby 1.8.7 (2009-06-12 patchlevel 174) [universal-darwin10.0]

$ which rvm-auto-ruby
/Users/cczona/.rvm/bin/rvm-auto-ruby

$ ls -lalphG /Users/cczona/.rvm/bin/rvm-auto-ruby
-rwxr-xr-x  1 cczona  admin   688B Sep 22 17:18 /Users/cczona/.rvm/bin/rvm-auto-ruby

$ rvm use default
Using /Users/cczona/.rvm/gems/ruby-1.9.2-p290 with gemset global

$ rvm info

ruby-1.9.2-p290@global:

  system:
    uname:       "Darwin New-Moon-Rising.local 10.8.0 Darwin Kernel Version 10.8.0: Tue Jun  7 16:33:36 PDT 2011; root:xnu-1504.15.3~1/RELEASE_I386 i386"
    bash:        "/bin/bash => GNU bash, version 3.2.48(1)-release (x86_64-apple-darwin10.0)"
    zsh:         "/bin/zsh => zsh 4.3.9 (i386-apple-darwin10.0)"

  rvm:
    version:      "rvm 1.8.3 by Wayne E. Seguin ([email protected]) [https://rvm.beginrescueend.com/]"

  ruby:
    interpreter:  "ruby"
    version:      "1.9.2p290"
    date:         "2011-07-09"
    platform:     "x86_64-darwin10.8.0"
    patchlevel:   "2011-07-09 revision 32553"
    full_version: "ruby 1.9.2p290 (2011-07-09 revision 32553) [x86_64-darwin10.8.0]"

  homes:
    gem:          "/Users/cczona/.rvm/gems/ruby-1.9.2-p290@global"
    ruby:         "/Users/cczona/.rvm/rubies/ruby-1.9.2-p290"

  binaries:
    ruby:         "/Users/cczona/.rvm/rubies/ruby-1.9.2-p290/bin/ruby"
    irb:          "/Users/cczona/.rvm/rubies/ruby-1.9.2-p290/bin/irb"
    gem:          "/Users/cczona/.rvm/rubies/ruby-1.9.2-p290/bin/gem"
    rake:         "/Users/cczona/.rvm/rubies/ruby-1.9.2-p290/bin/rake"

  environment:
    PATH:         "/Users/cczona/.rvm/gems/ruby-1.9.2-p290@global/bin:/Users/cczona/.rvm/rubies/ruby-1.9.2-p290/bin:/Users/cczona/.rvm/bin:.:/usr/local/bin:/Users/cczona/bin:/usr/libexec:/Developer/Tools:/Library/PEAR/bin:/Users/cczona/.gem/ruby/1.9/bin:/Users/cczona/.gem/ruby/1.8/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/X11/bin"
    GEM_HOME:     "/Users/cczona/.rvm/gems/ruby-1.9.2-p290@global"
    GEM_PATH:     "/Users/cczona/.rvm/gems/ruby-1.9.2-p290@global:/Users/cczona/.rvm/gems/ruby-1.9.2-p290@global"
    MY_RUBY_HOME: "/Users/cczona/.rvm/rubies/ruby-1.9.2-p290"
    IRBRC:        "/Users/cczona/.rvm/rubies/ruby-1.9.2-p290/.irbrc"
    RUBYOPT:      ""
    gemset:       "global"