Valid duration rejected by validation

[freshehr]

See attached .opt template and xml instance. Note that this was posted as XML - did not use FLAT JSON.

Error returned (tries with a few valid ISO duration strings) 

<title>Error 500 #1.0.0 Invocation exception to method:create:java.lang.IllegalArgumentException: Could not parse
		supplied content:java.lang.IllegalArgumentException: failed to create new instance of DV_DURATION:
		IllegalArgumentException: Wrong duration format: &quot;P4D&quot;, valueMap: {
		accuracy=java.lang.Float:0.0,
		value=java.lang.String:&quot;P4D&quot;}</title>

Archive.zip

[freshehr]

Is it as simple as the ISO string being passed in with enclosing single Quotes? i.e 'P4D' rather than P4D?? looking at the openEHR java lib code that would be my reading as it does not place any quotes when generating the error message.

public static DvDuration getInstance(String value) {
		if (value == null) {
			throw new IllegalArgumentException("null value");
		}

		if (!value.matches(PATTERN)) {
			throw new IllegalArgumentException("Wrong duration format: "
					+ value);
		}