rebalance button does not work after click failover

Created an attachment (id=417)
diag on ubuntu 10.04 64bit

Install ns server 1.6.0beta3a-76 on rhel 5.4 32bit and ubuntu 10.04 64bit (call A & B).
Go through initial setup on both node A & B.
On node A (ubuntu), click add server button to add node B to node A.
Click rebalance button on node A. The rebalance process is ok. I can see both node A and node B on server page of node A and node B.
Shutdown node B by uninstall ns_server
On node A, I see node B downs (as expected).
Click "Fail Over" of node B on A.
Click "Rebalance" button but nothing happens.
http://screencast.com/t/MDhlNmNj