Strange currency exchange behavior

I have Australian dollars as the default currency. On an item with a price of A$110, when I switch to US$, the price goes up a bit, to $112.18, when it should go down a bit. Same prob with euro, pound, etc. What could cause this?
http://www.glasscrafts.com.au/store/ (password-protected for now, use log-in: admin, testpw)
TIA, Jen

Did you update currencies??

Yep, a few times, makes no difference.

This is my last bug before I can go live with my store so does anyone have any ideas? I'm not allowing purchasing online by OS customers but I want them to be able to price the item they want and email for a quote for delivery, so I don't want to remove this sidebox. Anyone?

What are the exchange rates set in your admin for each currency?

Your "default" currency needs to be set to 1.000000 otherwise all the other rates are calculated from a different base.

My default currency, AU$, is set to 1.0000 and I have updated the exchange rates several times, to no avail. Unfortunately our server is down tonight but I will doublecheck tomorrow what the stated exchange rates are. Thanks.

OK, here's my Currencies page, after another "update currencies":

My head's starting to spin. Is this right?

The automated process goes to xe.com to check its rates, or oanda.com if there is a problem reaching xe.

If the numbers you're getting via the automated update are incorrect, then you're free to set the correct numbers manually. Just edit each currency individually and set the appropriate rate relative to your default currency.

OK, thanks, will do.
I understand that exchange rates need to be updated manually so I need to go in and change them every day, yes? Even though, on my site, it doesn't affect purchase price as we're only accepting orders from Australians in AU$. I'm just putting the currency sidebox there as a service to OS customers.

Is it common for the automatic update to fail like this?

jenpen:

I understand that exchange rates need to be updated manually so I need to go in and change them every day, yes?Daily? I guess if your currencies are that volatile, sure. But generally most exchange rates fluctuate only a little each day ... so unless your prices are in thousands of dollars a daily update is probably way overkill. Once every couple of weeks or even monthly may suffice, depending on the markets.

jenpen:

Even though, on my site, it doesn't affect purchase price as we're only accepting orders from Australians in AU$. I'm just putting the currency sidebox there as a service to OS customers. I'm not sure what "OS customers" means, but I assume you're certain that your customers won't be confused when they can look at prices in various currencies but only purchase in AUD.

jenpen:

Is it common for the automatic update to fail like this?Not as far as I've seen.

Dr Byte, thanks for all your attention to this. Aren't you up late?
Sorry, over here OS means overseas, I should have said international. We are only accepting orders from people with Australian delivery addresses, but are inviting international customers to email us for a shipping quote and will handle these offline. Long story I won't bore you with, but it's basically because our parcels are very big and there's an idiosyncracy with the Australia Post Module which won't accept parcels with such a large deadweight, even though our post office does.
Anyway, about 98% of our online sales are within Australia.
If we get more attention internationally, we may review the situation.
I have left the Currency sidebox there to help those international customers work out the cost in their own currency, even though they can't place an online order.

Thanks for the clarification.