For classes with Release method
VFP resolve cross objects reference deadlock;
or when you release a LINKED variable to a scx form.

X = CREATEOBJECT("form")
y = CREATEOBJECT("form")
Addproperty(m.x,"crossref",m.y)
Addproperty(m.y,"crossref",m.x)

* now i have a cross
x.Release
y.Release
* and VFP put NULL on all references
? m.y,m.x

Fabio