using foreign currencies

Thanks to the blog at http://moneydance.com/blog/archives/199 I finally learned how to use foreign currencies in Moneydance. This was great because I had just travelled to the Azores and needed to record my ATM transactions in Moneydance.  As the blog suggested I created a master bank account named "Foreign Currencies" and a sub-account for Euros.  I entered my ATM transactions in the Euros account and set the category to "Vacation." Then I had to transfer the money from my regular old American bank account to the Euros account. I created the transaction, set the category to the Euros account, entered the amount in USD and exchange rate as 1.3514. Moneydance conveniently displayed what that dollar amount converted to in Euros so I knew I entered the correct amount in US Dollars. I then pre
 ssed Enter to record the transaction. What I've noticed is the Euros account displays the exchange rate as 1.3514 while the Dollars account displays the exchange rate as 0.739973. That's fin
 e and somewhat expected because 0.739973 is the reciprocal of 1.3514. The problem is that when I edit the transfer transaction in my regular old American bank account Moneydance changes the exchange rate to 1.38293459 which is not the reciprocal of 1.3514.  How do I get Moneydance to stop changing the exchange rate whenever I edit one of these transactions?

-SteveL