Tkinter callback caused abnormal program termination

[John Pote]

Running my programme in Python 2.3.4 I received the following msg in the 
consol :-
(Pent III running W2K prof)

"""
Exception in Tkinter callback
Traceback (most recent call last):
  File "c:\apps\python\234\lib\lib-tk\Tkinter.py", line 1345, in __call__
    return self.func(*args)
  File "c:\apps\python\234\lib\lib-tk\Tkinter.py", line 459, in callit
    self.deletecommand(tmp[0])
AttributeError: 'str' object has no attribute 'deletecommand'
UpdateStringProc should not be invoked for type option

abnormal program termination
"""
There was no other traceback information.

Could this be related to lines of the ilk:-
  self.infoSpd.config(text="%d.%01d"%spd)
where infoSpd is a Tkinter Label object placed using the grid manager.

Thousands of these updates were performed so the labels displayed progress 
through a memory dump of a system accessed through a serial port.

I had trouble before with Python versions 2.2.1 and 2.2.3 where commenting 
out these Label updates stopped the system crashing and it was happy to run 
for hours performing tests on the external hardware. (an embedded data 
logger I'm developing)

Anyone any thoughts?

John