After running the latest 5.2.4 update on my site, I began receiving errors that payment processing company did not support the currency I was passing on to it. I am in the USA, and I've always had USD as my ONLY and default currency. After seeing this error, I went and checked, and the default base currency in SETUP/CONFIGURATION has nothing listed, and no way to specify ANY currency at all. Beyond that, I went into Manage Products and discovered that ALL the products in my database had now been set to "AED" as the default instead of "USD". After changing ALL my products over to use USD as the default currency, for ALL the billing plans, I was able to get everything working again, but I thought I should make everyone aware of this. I believe it is all because I had no BASE currency set anymore, and NO WAY to set one (there were drop down lists to select, no text boxes, etc.) but I can't be sure. What is interesting is that AFTER I set all my products to use USD in their profiles, the Base Currency now reads USD as it should. Just a heads up!