The second one hung (reboot required):
sending from @2013-03-06-114735 to Big@2013-03-06-124445
receiving incremental stream of Big@2013-03-06-124445 into Safe@2013-03-06-124445
1,57MiB 0:00:04 [ 370kiB/s] [ 370kiB/s] [> ] 0%
The rollback option (-F) has no effect on the hanging problem. I verified that a while back.