state-dependant datagrid inside module, itemRenderer does not access parentDocument consistantly

myDataGrid is inside myModule.
myDataGrid displays according to a state, and has an itemRenderer in it.

The itemRenderer is attempting to access a var in myDataGrid like so:
this.grid.dataGrid.parentDocument.myVar

The datagrid displays correctly when the state is entered for the first time. But consecutive times the state is re-entered, flash player locks up.
This is because ...parentDocument is referencing the Module class instead of myModule.

Work around:

var _parent:DisplayObjectContainer = this.grid.dataGrid.parent;
var _myVar:MyVar
while (_parent != this.parentApplication)
{
if (_parent.hasOwnProperty("myVar"))

{ _myVar= _parent["myVar"]; break; }

else _parent = _parent.parent;
}