diff -Naur orig/email_template/email_template.py new/email_template/email_template.py
--- orig/email_template/email_template.py	2012-06-07 01:15:11.500516678 +0100
+++ new/email_template/email_template.py	2012-06-07 01:26:50.535721216 +0100
@@ -340,7 +340,9 @@
         attachments = {}
         # Add report as a Document
         if template.report_template:
-            report_name = template.report_name
+            report_name = self.render_template(cr, uid, template.report_name,
+                                                 template.model, res_id, context=context) \
+                                                 or False
             report_service = 'report.' + report_xml_pool.browse(cr, uid, template.report_template.id, context).report_name
             # Ensure report is rendered using template's language
             ctx = context.copy()
@@ -395,9 +397,11 @@
                     'res_model': mail_message._name,
                     'res_id': msg_id,
             }
-            if context.has_key('default_type'):
+            if context and context.has_key('default_type'):
                 del context['default_type']
             attachment_ids.append(ir_attachment.create(cr, uid, attachment_data, context=context))
+        if attachment_ids:
+            mail_message.write(cr, uid, msg_id, { 'attachment_ids': [(6, 0, attachment_ids)]}, context=context)
         if force_send:
             mail_message.send(cr, uid, [msg_id], context=context)
         return msg_id