ruby-on-rails - autotest-growl not reporting any failures or errors

Question

I have autotest set up and it's running fine and reporting errors correctly, but the growl notification always ignores any failures and errors, which makes it completely useless..

autotest -f
...
==============================================================================
pass: 2,  fail: 0,  error: 1
total: 3 tests with 173 assertions in 17.747792 seconds
==============================================================================

But the growl notifications never report any errors:

TRUNK: All unit tests passed.
173 assertions in 3 tests

Here are my gems:

autotest-fsevent (0.2.8)
autotest-growl (0.2.16)
autotest-rails (4.1.2)
growl_notify (0.0.3)
redgreen (1.2.2)
ZenTest (4.9.0)

.autotest

require "autotest/fsevent"
require "autotest/growl"
require "redgreen/autotest"
...

Other stuff

ruby 1.8.7 (2012-02-08 patchlevel 358) [universal-darwin12.0]
Rails 2.3.14
OS X 10.8.2
Growl 2.0.1

Help!