[NetBeans 6.5M1, Build 200806270102, JDK 1.6.0]

This was found when testing http://wiki.netbeans.org/TS_61_RubyDebugger Ruby Debugger - Section 9, Task 10.

To reproduce:
1) Have a Ruby project on Built-in JRuby platform with main.rb file like:

  def fib(n)
    if n<2 then #BREAKPOINT HERE 
      return n
    else
      return fib(n-1) + fib(n-2)
    end
  end

  5.times do |i|
    puts fib(i) #BREAKPOINT HERE
  end

2) Call debug, in Breakpoints view call context menu > Disable all

3) Call context menu > Enable all
ERROR: IDE freezes for 15 seconds

ERROR: Dialog appears 'Problem occured during debugger start: Unable to read added breakpoint number in the specified 
timeout [15s]' (image attached)
ERROR: org.rubyforge.debugcommons.RubyDebuggerException occurs (Exception and thread dump attached)

ERROR: Debugging functions are now out of order (Continue, Step...).
NOTE: Disable all and Enable all works fine now :)

ERROR: This also causes the debug task to become unkillable exactly the same way as described in Issue 138449. Have to 
kill it manually in OS.

NOTE: This does not happen with Ruby 1.8.6-p111 platform