rebalance repeated failed when add nodes back into cluster

Environment: 12 ubuntu servers with 4 GB RAM
Group 1
10.3.3.61
DISTRIB_RELEASE=10.04
10.3.3.74
DISTRIB_RELEASE=10.04
10.3.3.67
DISTRIB_RELEASE=10.04

Group 2
10.3.3.63
DISTRIB_RELEASE=10.04
10.3.4.219
DISTRIB_RELEASE=10.04
10.3.4.220
DISTRIB_RELEASE=10.04

Group 3
10.3.3.75
DISTRIB_RELEASE=10.04
10.3.3.71
DISTRIB_RELEASE=10.04
10.1.2.85
DISTRIB_RELEASE=12.04

Group 4
10.3.3.58
DISTRIB_RELEASE=10.04
10.3.3.64
DISTRIB_RELEASE=10.04
172.23.105.228
DISTRIB_RELEASE=12.04

Setup:
Install couchbase server 2.5.0-979 on 12 servers
Create 12 nodes cluster with zone setup in environment above
Create 2 buckets, default and sasl with 3 replica at each bucket.
Load 100 K items to each bucket
Verified replica distributed correctly

Tests:
Shutdown couchbase server in all nodes of group 4
Failover all down nodes in group 4
Rebalance. Rebalance completed
Verified replica distributed correctly
Verified no data lost.

Start couchbase server in all nodes of group 4 that I shut them down before.
Add all 3 nodes to group 4.
Rebalance ==> Failed (may due to time zone at one added node does not sync. Fixed this time zone)
Verified time is sync at all nodes
Rebalance again and again ==> still failed with error

Rebalance exited with reason {badarg,
[{erlang,'++',
[{'EXIT',

Link to manifest file of this build http://builds.hq.northscale.net/latestbuilds/couchbase-server-enterprise_x86_64_2.5.0-979-rel.deb.manifest.xml