I haven't heard of this happening. Deployments should clean up resources associated with them. However it's possible that something in the deployment can't be GC'd if it itself is holding on to some resource. You'd want to attach a profiler or something to see what's hanging around after a redeploy.
James R. Perkins
As it is a couchbase Exception I would check this side also.
As James mentioned a profiler snapshot taken before and after undeploy/redeploy might help to find the issue.
Often it is a problem when applications do something against the spec like thread control or thread-local variables which are not cleaned up.