[ruby-talk:20787] memory leak in simple tk script with ruby snapshot?

Using ruby 1.7.1 (2001-09-01) [i686-linux] with tk and the following
(trival) script I see an apparent memory leak.

(Apologies if this is something wrong with my code not freeing memory
since I am new to ruby)

####################################################################
#!/usr/local/bin/ruby
# $Id$
#

require 'tk'

$epoch = Time.at(1000000000)

root = TkRoot.new { title "U1E9 countdown" }          

$label = TkLabel.new(root) {                        
  pack { padx 15 ; pady 15; side 'left' } 
  proc{tick}
}                   

TkButton.new {
  text 'quit'
  command proc {
    root.destroy
  }
  pack('side'=>'left','fill'=>'both','expand'=>'yes')
}

Tk.after 50, proc {tick}

def tick
  Tk.after 50, proc{tick}
  timediff = $epoch - Time.now
  days = (timediff/86400).to_i; timediff%=86400
  hours = (timediff/3600).to_i; timediff%=3600
  mins = (timediff/60).to_i; timediff%=60
  secs = timediff.to_i
  $label.configure('text'=>"#{days} day(s), #{hours} hour(s), #{mins} min(s) and #{secs} sec(s) left")
end

root.bind "Control-c", proc{root.destroy}

Tk.mainloop                                

##########################################################

-- 
1024/D9C69DF9 steve mynott [e-mail]

    whenever people agree with me i always feel i must be wrong.
        -- oscar wilde