The following tested using Immutant 1.x.incremental.1009 (PuntoBueno)

init.clj

(ns immutant.init
  (:require [clj-time.core :as dt]
            [immutant.messaging :as msg]))

(msg/start "/queue/a-queue")
(msg/listen "/queue/a-queue" #(println "received: " %))

(msg/publish "/queue/a-queue" {:created (dt/now)}) ; gives a stacktrace

project.clj

(defproject joda "0.1.0-SNAPSHOT"
  :description "FIXME: write description"
  :url "http://example.com/FIXME"
  :license {:name "Eclipse Public License"
            :url "http://www.eclipse.org/legal/epl-v10.html"}
  :dependencies [[org.clojure/clojure "1.5.1"]
                 [clj-time "0.6.0"]])

stacktrace

11:21:24,660 WARN  [org.immutant.messaging.MessageProcessor] (Thread-1 (HornetQ-client-global-threads-365129326)) Unhandled exception thrown from onMessage: java.lang.RuntimeException: Unexpected error processing message from: /queue/a-queue.
	at org.immutant.messaging.MessageProcessor.onMessage(MessageProcessor.java:63) [immutant-messaging-module.jar:1.x.incremental.1009]
	at org.projectodd.polyglot.messaging.BaseMessageProcessor.onMessage(BaseMessageProcessor.java:132)
	at org.hornetq.core.client.impl.ClientConsumerImpl.callOnMessage(ClientConsumerImpl.java:1016) [hornetq-core-client-2.3.0.CR1.jar:]
	at org.hornetq.core.client.impl.ClientConsumerImpl.access$400(ClientConsumerImpl.java:52) [hornetq-core-client-2.3.0.CR1.jar:]
	at org.hornetq.core.client.impl.ClientConsumerImpl$Runner.run(ClientConsumerImpl.java:1161) [hornetq-core-client-2.3.0.CR1.jar:]
	at org.hornetq.utils.OrderedExecutorFactory$OrderedExecutor$1.run(OrderedExecutorFactory.java:106) [hornetq-core-client-2.3.0.CR1.jar:]
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [rt.jar:1.7.0_40]
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [rt.jar:1.7.0_40]
	at java.lang.Thread.run(Thread.java:724) [rt.jar:1.7.0_40]
Caused by: java.lang.RuntimeException: Invalid edn-encoded data (type=class java.lang.String): {:created #<DateTime 2013-10-03T09:21:24.542Z>}
	at immutant.codecs$eval2409$fn__2410.doInvoke(codecs.clj:79)
	at clojure.lang.RestFn.invoke(RestFn.java:423) [clojure-1.5.1.jar:]
	at clojure.lang.MultiFn.invoke(MultiFn.java:231) [clojure-1.5.1.jar:]
	at immutant.messaging.codecs$eval2509$fn__2510.invoke(codecs.clj:88)
	at clojure.lang.MultiFn.invoke(MultiFn.java:227) [clojure-1.5.1.jar:]
	at immutant.messaging.codecs$decode_with_metadata.invoke(codecs.clj:106)
	at immutant.messaging.codecs$decode_if.invoke(codecs.clj:115)
	at immutant.messaging$listen$fn__2558$loading__4910__auto____2561$fn__2562.invoke(messaging.clj:206)
	at clojure.lang.AFn.applyToHelper(AFn.java:161) [clojure-1.5.1.jar:]
	at clojure.lang.AFn.applyTo(AFn.java:151) [clojure-1.5.1.jar:]
	at clojure.core$apply.invoke(core.clj:617) [clojure-1.5.1.jar:]
	at clojure.core$with_bindings_STAR_.doInvoke(core.clj:1788) [clojure-1.5.1.jar:]
	at clojure.lang.RestFn.applyTo(RestFn.java:142) [clojure-1.5.1.jar:]
	at clojure.core$apply.invoke(core.clj:621) [clojure-1.5.1.jar:]
	at clojure.core$bound_fn_STAR_$fn__4102.doInvoke(core.clj:1810) [clojure-1.5.1.jar:]
	at clojure.lang.RestFn.invoke(RestFn.java:408) [clojure-1.5.1.jar:]
	at org.projectodd.shimdandy.impl.ClojureRuntimeShimImpl.invoke(ClojureRuntimeShimImpl.java:91) [shimdandy-impl.jar:]
	at org.immutant.messaging.MessageProcessor.onMessage(MessageProcessor.java:51) [immutant-messaging-module.jar:1.x.incremental.1009]
	... 8 more
Caused by: clojure.lang.ExceptionInfo: Unreadable form {:type :reader-exception}
	at clojure.core$ex_info.invoke(core.clj:4327) [clojure-1.5.1.jar:]
	at clojure.tools.reader.reader_types$reader_error.doInvoke(reader_types.clj:217)
	at clojure.lang.RestFn.invoke(RestFn.java:423) [clojure-1.5.1.jar:]
	at clojure.tools.reader.impl.commons$throwing_reader$fn__2064.doInvoke(commons.clj:119)
	at clojure.lang.RestFn.invoke(RestFn.java:439) [clojure-1.5.1.jar:]
	at clojure.tools.reader.edn$read_dispatch.invoke(edn.clj:56)
	at clojure.tools.reader.edn$read_delimited.invoke(edn.clj:160)
	at clojure.tools.reader.edn$read_map.invoke(edn.clj:178)
	at clojure.tools.reader.edn$read.invoke(edn.clj:360)
	at clojure.tools.reader.edn$read.invoke(edn.clj:349)
	at clojure.tools.reader.edn$read_string.invoke(edn.clj:386)
	at immutant.codecs$eval2409$fn__2410.doInvoke(codecs.clj:26)
	... 25 more