title: Bad expiration date format, and this expiration date will be ignored
body: <p>I have created a BPEL process with wait activity, there are input for process start time (datetime) and interval(duration). while creating an instance(workitem) in process, it moves to wait and on console i got the error</p>
  
  <pre><code>&lt;Mar 23, 2011 9:27:53 PM SGT&gt; &lt;Error&gt; &lt;oracle.soa.bpel.engine.bpel&gt; &lt;BEA-000000&gt;
   &lt;&lt;BPELReceiveWMP::__defineExpirationDate&gt; Bad expiration date format, and this
  expiration date will be ignored
  java.lang.IllegalArgumentException: Duration has to start with 'P'.
  </code></pre>
  
  <p>Input payload for process is:</p>
  
  <pre><code>&lt;inputVariable&gt;  &lt;part  name="payload"&gt;  &lt;ns1:process&gt;  &lt;ns1:startDate&gt;2011-03-23T16:30:00.000+08:00&lt;/ns1:startDate&gt;  &lt;ns1:interval&gt;PT2M&lt;/ns1:interval&gt;  &lt;/ns1:process&gt;  &lt;/part&gt;  &lt;/inputVariable&gt;
  </code></pre>
  
  <p>And in wait have putted </p>
  
  <blockquote>
    <p>string(bpws:getVariableData('inputVariable','payload','/client:process/client:startDate'))</p>
  </blockquote>
  
  <p>expression in "for" column</p>
  
  <p><em>WaitForStart (pending) 
  Mar 23, 2011 9:27:53 PM Bad expiration date "2011-03-23T16:30:00.000+08:00" 
  Mar 23, 2011 9:27:53 PM Waiting for the expiry time "never".</em> </p>
  
  <p>environment is: 
  SOA 11.1.1.3.0
  Jdeveloper: 11.3</p>