// Fixed Division by ZERO ...

classes/Tools.php

@@ -550,8 +550,9 @@ class ToolsCore
 			$amount *= $currency_to->conversion_rate;
 		else
 		{
+            $conversion_rate = ($currency_from->conversion_rate == 0 ? 1 : $currency_from->conversion_rate);
 			// Convert amount to default currency (using the old currency rate)
-			$amount = Tools::ps_round($amount / $currency_from->conversion_rate, 2);
+			$amount = Tools::ps_round($amount / $conversion_rate, 2);
 			// Convert to new currency
 			$amount *= $currency_to->conversion_rate;
 		}