Hi,
Ok, now I get it.
The thing is that you have several discounts applying to the prices.
Here is how the system works:
The system load the prices of the product and take the price in the current currency. If none is available, it takes another one and convert it to the current currency.
Then, it loads all the discounts applying to the product. It then converts them all to the current currency and pick the most interesting one and apply it to the price of the product.
So since you have one discount per currency, the system will actually always pick the one which offers the most important discount when you convert them to the current currency.
I suppose that you expected that it would pick the discount of the current currency and discard the others instead which is why you have a result you didn't expect.
If you disable the other disounts and leave only the discount of the current currency, then you should always have the result you expect.
Frankly, we didn't thought of that so far. Most merchants uses percentages, or directly set the prices they want in the products, and when they don't, they usually use only one currency.
I suppose that you think that it would make sense to have the system works for the discounts like it does for the prices and first pick the discounts of the current currency before checking the others.
I kind of agree with you on that.
I've added a patch for that.
Download the install package again on our website and install it on yours and that will add the patch.