In the below "nodetool ring" output, machine 18 was told to loadbalance over an hour ago.  It won't actually leave the ring.  When I first told it to loadbalance, the cluster was under heavy write load; I've turned off the write load, but the node won't actually leave, still.  Help?
(It also collected 3.6G of load even though automatic bootstrapping is disabled -- but this node had belonged to the cluster before, so maybe cleaning out /var/lib/cassandra/* wasn't enough to prevent the node from rejoining and taking data responsibility?)

$ nt ring
Address         Status State   Load            Token
X.22       Up     Normal  561.98 GB       42535295865117307932921825928971026431
X.18       Up     Leaving 3.68 GB         57974296897141728657026715086733697169
X.21       Up     Normal  523.78 GB       85070591730234615865843651857942052862
X.20       Up     Normal  539.24 GB       127605887595351923798765477786913079293
X.19       Up     Normal  505.12 GB       170141183460469231731687303715884105727

$ nodetool -h X.18 netstats
Mode: Leaving: streaming data to other nodes
Nothing streaming to /X.21
Nothing streaming to /X.20
Not receiving any streams.
Pool Name                    Active   Pending      Completed
Commands                        n/a         0          12246
Responses                       n/a         0       22595947