Print Attachment Button

Hi,
I've been trying to be able to print an attachment imbedded in a LiveCycle form using the following JavaScript on the click event of a button:
 
var oThis = event.target;
var d = oThis.dataObjects;
var oDoc = oThis.openDataObject(d[0].name);
try {
var pp = oDoc.getPrintParams();
pp.interactive = pp.constants.interactionLevel.full;
oDoc.print(pp);
oDoc.closeDoc();
} catch(e) { app.alert("Operation failed------>"+e.name);}
 
The code assumes the user wants to print the first attachement, it successfully opens and returns the DataObject object for that attachement yet when I pass the object to the print method it returns a 'NotAllowedError' error. The Acrobat 8.0 API doesn't say it shouldn't work, the only constraints seam to be if the interactionLevel is set to silent.
 
Any help would be appreciated.
 
Thanks.
 
Kyle