Aptana 3 ruby debugger - Exception in DebugThread loop: undefined method `is_binary_data?'

Question

I'm trying to debug simple ruby file in Aptana 3.

class HelloWorld

def initialize()

end

def greet()
  puts "hello world"
end
end

h=HelloWorld.new
h.greet

breakpoint is set to

h.greet

after I started debug, debugger starts, but when it tries to initialize ruby class, debugger disconnect with message

Fast Debugger (ruby-debug-ide 0.4.9) listens on :54749
Exception in DebugThread loop: undefined method `is_binary_data?' for "#<HelloWorld:0x85915fc>":String  

when I set breakpoint to

h=HelloWorld.new

debugger starts, but after I stepped into initialize() constructor, it disconnects with previous message

My gems list:

*** LOCAL GEMS ***

archive-tar-minitar (0.5.2)
bigdecimal (1.1.0)
columnize (0.3.6)
io-console (0.3)
json (1.5.4)
linecache19 (0.5.13)
minitest (2.5.1)
rake (0.9.2.2)
rdoc (3.9.4)
ruby-debug-base19 (0.11.26)
ruby-debug-ide19 (0.4.12)
ruby-debug19 (0.11.6)
ruby_core_source (0.1.5)

I have successfully applied these instructions, to solve problems with debugging but I still got this exception message

Any answer is welcome which shed a light to this problem.

Thank you.