Modifying remote cluster settings from non-ssl to ssl immidiately after upgrade from 2.5.1-3.0.0 failed but passed after waiting for 2 minutes.

Setting up non-ssl XDCR between Source and Destination with version 2.5.1-1083.
Upgrade remote clusters to 3.0.0-973 and change settings to SSL failed immediately.

[2014-07-17 10:28:29,416] - [rest_client:747] ERROR - http://10.3.5.61:8091/pools/default/remoteClusters/cluster0 error 400 reason: unknown {"_":"Error {{tls_alert,\"unknown ca\"},\n [{lhttpc_client,send_request,1,\n [

,\n

]},\n {lhttpc_client,request,9,\n [

,\n

]}]} happened during REST call get to http://10.3.3.126:18091/pools."}
ERROR
[2014-07-17 10:28:29,418] - [xdcrbasetests:158] WARNING - CLEANUP WAS SKIPPED

======================================================================
ERROR: offline_cluster_upgrade (xdcr.upgradeXDCR.UpgradeTests)
----------------------------------------------------------------------
Traceback (most recent call last):
File "pytests/xdcr/upgradeXDCR.py", line 195, in offline_cluster_upgrade
self._modify_clusters(None, self.dest_master, remote_cluster['name'], self.src_master, require_encryption=1)
File "pytests/xdcr/xdcrbasetests.py", line 1123, in _modify_clusters
demandEncryption=require_encryption, certificate=certificate)
File "lib/membase/api/rest_client.py", line 835, in modify_remote_cluster
self.__remote_clusters(api, 'modify', remoteIp, remotePort, username, password, name, demandEncryption, certificate)
File "lib/membase/api/rest_client.py", line 822, in __remote_clusters
raise Exception("remoteCluster API '

remote cluster' failed".format(op))
Exception: remoteCluster API 'modify remote cluster' failed

----------------------------------------------------------------------
Ran 1 test in 614.847s

[Jenkins]
http://qa.hq.northscale.net/job/centos_x64--104_01--XDCR_upgrade-P1/22/consoleFull

[Test]
./testrunner i centos_x64104_01-XDCR_upgrade-P1.ini get-cbcollect-info=True,get-logs=False,stop-on-failure=False,get-coredumps=True,upgrade_version=3.0.0-973-rel,initial_vbuckets=1024 -t xdcr.upgradeXDCR.UpgradeTests.offline_cluster_upgrade,initial_version=2.5.1-1083-rel,replication_type=xmem,bucket_topology=default:1>2;bucket0:1><2,upgrade_nodes=dest;src,use_encryption_after_upgrade=src;dest

Workaround: I put wait of 120 seconds after upgrade and before changing XDCR seetings. and test passed.

Question: Is it expected behavior after upgrading from 2.5.1-1083 -> 3.0.0, since same test passes with no additional wait from as upgrading from 2.0 -> 3.0 or 2.5.0-3.0?

Issue occuring only for upgrade from 2.5.1-1083-rel -> 3.0.0-973-rel.