pickle magically not working

[Michael Janssen]

Hello

at least i've solved it (as a workaround), but it's pretty annoying. 
Maybe someone has an answere :-)

i wanted to pickle a dictionary. The code was fine on my own maschine 
but throwing RuntimeError: "maximum recursion depth exceeded" on other 
maschines (same Linux, same Python-Version 2.2).

The mindthrilling thing was (and is), that i can copy the dictionary 
content with mouse2 into a working dictionary. Original dic still 
refused working. Have a look:

m is a single-key version of the bad dic. mm is hand-made

>>> m == mm
1
>>> m
{(2002, 9, 16, 0, 0, 0, 0, 259, 1): {'virus': 1, 'batches': 186, 
'scan': 152, 'mail': 307, 'spam': 0, 'bytes': 6213773}}
>>> mm
{(2002, 9, 16, 0, 0, 0, 0, 259, 1): {'virus': 1, 'batches': 186, 
'spam': 0, 'mail': 307, 'scan': 152, 'bytes': 6213773}}
>>> try: pickle.dump(m, fo); print "functional"
... except RuntimeError: print "not functional"
...
not functional
>>> try: pickle.dump(mm, fo); print "functional"
... except RuntimeError: print "not functional"
...
functional

copy.copy or copiing via:

    d = {}
    for key in dump_dic.keys():
        d[key] = dump_dic[key]

doesn't help. finally i've improved ;-) the copiing-code to:
    d = {}
    for key in dump_dic.keys():
        d[key[:]] = dump_dic[key]

i.e. making copies of the keys (which are tupel as returned by 
time.localtime(), by the way).

Pickling is now functional, but the question remains: 
  *what can cause this???*

Furthermore: is there a way to examine somewhat deep data-structure, or 
is it more reliable to blame voodoo and "computer-logik" for this ;-)

Michael

PS: Don't ask me, how i've build those nasty dics. Hundreds lines of 
slightly confused code have done it ;-)