99% of my sales are in the US, but I have a couple of important customers in other parts of the world. I therefore offer the option to customers to see the pricing in their local currency, but I am clear that the transactions are in $US. Until just recently, invoices from non-US customers would always show up in my Admin as $US. I just received a transaction from Australia where the invoice is in $AUS.

I use PayPal IPN. Most of my customers' transactions are listed as "cart". This last Australian purchase was listed as "expresscheckout" Is that related?

I cannot remember making any change that would cause this. Any ideas where I should look?