[Bf-python] Strange crash

[Jordi Rovira i Bonet]

In short:

0x082d222d in visit_decref (op=0x83786c0, data=0x0) at 
Modules/gcmodule.c:185
185     Modules/gcmodule.c: No such file or directory.
        in Modules/gcmodule.c
(gdb) backtrace 10
#0  0x082d222d in visit_decref (op=0x83786c0, data=0x0) at 
Modules/gcmodule.c:185
#1  0x0828a846 in dict_traverse (op=0x8402b7c, visit=0x82d221c 
<visit_decref>, arg=0x0) at Objects/dictobject.c:1589
#2  0x082d1618 in collect (young=0x8393300, old=0x839330c) at 
Modules/gcmodule.c:201
#3  0x082d1bc4 in collect_generations () at Modules/gcmodule.c:518
#4  0x082d208e in _PyObject_GC_New (tp=0x8386fc0) at Modules/gcmodule.c:879
#5  0x08281ecd in PyList_New (size=0) at Objects/listobject.c:71
#6  0x0822268a in nmface_from_data (mesh=0x8550ba8, vidxs=0xbfffe678, 
mat_nr=0 '\000', flag=0 '\000', tface=0x0, col=0x0)
    at ../../../../../source/blender/python/api2_2x/NMesh.c:914
#7  0x082226ff in nmface_from_shortdata (mesh=0x8550ba8, face=0x8593d08, 
tface=0x0, col=0x0) at 
../../../../../source/blender/python/api2_2x/NMesh.c:928
#8  0x08222af4 in new_NMesh_internal (oldmesh=0x858c324, dlm=0x0, 
extverts=0x0) at ../../../../../source/blender/python/api2_2x/NMesh.c:1062
#9  0x08222b73 in new_NMesh (oldmesh=0x858c324) at 
../../../../../source/blender/python/api2_2x/NMesh.c:1074
(More stack frames follow...)
(gdb) print *op
$1 = {ob_refcnt = 2, ob_type = 0x0}

When this happens:
    - while trying to build an nmesh, when trying to build a PyList. 
Random, because i've rmoved some calls and then it happens in another 
call to the creation of pylist somewhere else.

What i think:
    - for some reason it goes through the dictionary of types (seems 
related to garbage collecting) and it finds a null object type there 
that makes it crash.

Conditions:
    - I'm working with slightly modified CVS version, and connot say if 
it related to the recent addition of the PyType assignations, because 
now i'm doing more things in my script and the small test i was using 
still works. I've tried to remove the PyType assignements in the related 
python C modules implementation, (not all) and it persists.

What i need:
    - any idea please!

(bandoler)