From whiteboard/cframpton/adobe.next. Fix ListCollectionView bug. RTE happens because addAllAt() wasn't taking into account that some of the added items could be filtered out. Now, it checks the length as it is adding items. If the insertion index goes out of bounds because of filtering, it adds the rest of the items at the end.
incubator/flex/sdk/branches/develop/frameworks/projects/framework/src/mx/collections/ListCollectionView.as