Error with Tkinter and tkMessageBox

[Fabio Z Tessitore]

hi all,

this Tkinter very simple code work fine:

##########################
from Tkinter import *

win = Tk()
win.mainloop()
##########################

but if I try to open a message box, it happens:

Exception in Tkinter callback
Traceback (most recent call last):
  File "lib-tk/Tkinter.py", line 1348, in __call__
    return self.func(*args)
  File "/home/fabio/Desktop/prova.py", line 5, in reply
    showinfo(title='ciao', message='hello')
  File "lib-tk/tkMessageBox.py", line 84, in showinfo
    return _show(title, message, INFO, OK, **options)
  File "lib-tk/tkMessageBox.py", line 75, in _show
    res = Message(**options).show()
  File "lib-tk/tkCommonDialog.py", line 52, in show
    s = w.tk.call(self.command, *w._options(self.options))
TclError: bad pad value "2m": must be positive screen distance


##############################
from Tkinter import *
from tkMessageBox import *

def reply():
	showinfo(title='ciao', message='hello')

win = Tk()
but = Button(win, text='press me', command=reply)
but.pack()
win.mainloop()
##############################

these are versions:

python: 			2.4.4 or 2.5.1
Tkinter.TclVersion: 		8.4
Tkinter.TkVersion: 		8.4

can anyone help me?
thanks