If the mapping using IndirectList has listOrderfield != null then this flag indicates
whether the list in the db has invalid order:
either row(s) with null order value(s) or/and "holes" in order.
The flag may be set to true when the objects are read from the db.
When collection is updated the flag set to true causes updating of listOrderField of all rows in the db.
After update is complete the flag is set back to false.