I just picked one thread to be able to inform as many people as possible about my findings.

Following a bit the C000005 error story around on this form.
I've been enhancing my own framework with in my head the idea to let it inherit from another layer.!?
What I always did was a DODEFAULT() in most of the fox base methods of my subclassed set.
For example in my CustomBase::Init()

*---------------------------------
local llRetVal

llRetVal = dodefault()
if llRetVal
*-- Do some stuff
endif

return llRetVal
*----------------------------------

This is a bit the background.
Well for the custom class I just added this code recently.
Classes inhereting from my custom base working properly before went booming all of sudden.
Lucky Fox displayed the call stack, so I was right on track to find the offending object.

Removing the dodefault() - what in my case in fact called up to the Fox custom::Init() made my class working properly again.

??? That damn strange fox.
So I suspect the DODEFAULT() of being errornous.
Which was already the case in VFP5.0 where DODEFAULT() called up the wrong hierarchy ending up with very strange results.
BTW this was fixed in VFP5.0a so you should think VFP6.0 doesn't have any problems with that DODEFAULT().