replication chains seems to be broken for 3 vbuckets after rebalancing 3->4 nodes in replica 3

incremental rebalance with 2 replicas doesn't show huge gap between total_items and (items * replica factor) its < 0.05 percent

for 3 replica however the gap seems to be larger :
[2011-06-22 08:52:34,196] - [rebalance_helper] [47794844537072] - INFO - sum : 368440 and sum * replica_factor (3) : 1473760
[2011-06-22 08:52:34,197] - [rebalance_helper] [47794844537072] - INFO - master_stats : 1457474

its mismatch of 16286 or near 1 percent

to reproduce :

start from one node , add 100,000 itesm .
go to second node add another 100,000 items

you should see a mismatch when going from 3->4 nodes.