Using this method will fail as once docCur has been deleted you can't reference it when trying to get the next document.
Delete docCur ' so documents don't accumulate in cache
Set docCur = coll.GetNextDocument(docCur)
In the first version the previous object referenced by docNext is getting deleted.
'sets docCur to the object currently referenced by docNext
Set docCur = docNext
'sets docNext to next document in collection
Set docNext = coll.GetNextDocument(docCur)
'deletes the previous object referenced by docNext