Layout handle in transactinoal email not using the right theme

Question

{{layout area="frontend" handle="sales_email_order_invoice_items" invoice=$invoice order=$order}}

The above block/layout handle in my transactional email is using the base theme when the invoice is created - however strangely when the invoice is resent, it uses the correct theme. Both actions are being carried out in the admin.

I've tried:

{{layout area="frontend" package="foo" theme="bar" handle="sales_email_order_invoice_items" invoice=$invoice order=$order}}

but have had no luck.

Answer 1

It seems that just setting the 'Default' value under Configuration > General > Design is not quite enough for the transactional emails to use the correct theme. I needed to fill everything out: