ruby-processing regression between jruby 1.7.2 and 1.7.3?

output.txt

$ rvm use system
$ rp5 run test_sketch.rb 
RUBY_VERSION: 1.9.3
RUBY_PLATFORM: java
JRUBY_VERSION: 1.7.3
JRUBY_REVISION: dac429b

FDrawable stroke methods ==========
[]

$ rvm use jruby-1.7.2
$ rp5 run --jruby test_sketch.rb 
RUBY_VERSION: 1.9.3
RUBY_PLATFORM: java
JRUBY_VERSION: 1.7.2
JRUBY_REVISION: 302c706

FDrawable stroke methods ==========
[:appletStroke, :stroke_weight=, :stroke=, :set_no_stroke, :setStroke, :stroke_color=, :setStrokeWeight, :set_stroke, :applet_fill_stroke, :set_stroke_color, :setNoStroke, :appletFillStroke, :setStrokeColor, :set_stroke_weight, :strokeWeight=, :strokeColor=, :applet_stroke]

$ rvm use jruby-1.7.3
$ rp5 run --jruby test_sketch.rb 
RUBY_VERSION: 1.9.3
RUBY_PLATFORM: java
JRUBY_VERSION: 1.7.3
JRUBY_REVISION: dac429b

FDrawable stroke methods ==========
[:appletStroke, :stroke_weight=, :stroke=, :set_no_stroke, :setStroke, :stroke_color=, :setStrokeWeight, :set_stroke, :applet_fill_stroke, :set_stroke_color, :setNoStroke, :appletFillStroke, :setStrokeColor, :set_stroke_weight, :strokeWeight=, :strokeColor=, :applet_stroke]

test_sketch.rb

load_libraries :fisica
include_package "fisica"
# http://www.ricardmarxer.com/fisica/

def setup
  puts "RUBY_VERSION: #{RUBY_VERSION}"
  puts "RUBY_PLATFORM: #{RUBY_PLATFORM}"
  puts "JRUBY_VERSION: #{JRUBY_VERSION}"
  puts "JRUBY_REVISION: #{JRUBY_REVISION}"

  puts
  puts "FDrawable stroke methods =========="
  puts FDrawable.instance_methods.select {|m| m.match /stroke/i }.inspect
end

def draw
end

Normally the only reason to use an external jruby is to access ruby gems (ie libraries installed by the external jruby). The included jruby is jruby-complete, I've no idea why methods might be missing.