CURCY is causing PayPal Payments not to appear in checkout.

PayPal Payments does not appear as an option for customers to pay when they are in the checkout. This is the case, even though the PayPal Payments plugin is installed AND activated. Also, even though the PayPal Payments button does appear in the small drop-down cart at the top of the web-page, when you click on it, nothing happens. When CURCY is disabled, PayPal Payments works normally.