CBTransfer for disk+memory stuck when using UPR Flow control

version: 3.0.0-768, vbuckets=128

1. Set up 7 node cluster
2. Set up default bucket
3. Add 5K items with mutations
4. Run Cbtransfer for get disk+memory data
/opt/couchbase/bin/cbtransfer http://10.6.2.144:8091 csv:/tmp/8adec7a8-eb73-11e3-b12f-0050569702a8.csv -b default -u Administrator -p password --single-node

Step 4 hangs.

logs attached.

Mike noted that upr flow control was enabled for the bucket