Apple's way of converting currencies

I had to do some currency conversions today and I'm usually relying on Apple's Dashboard Widget "Unit Converter".
I had to convert British Pounds into US Dollars and got some strange numbers that didn't sound right. I then made following conversion from US Dollars into US Dollars and got some very interesting results.

Currency conversion - the Apple way

Now, Apple claims to get the data from Yahoo Finance although their website shows the real numbers:

Yahoo Currency conversion

I wonder if I'm the only one having that problem. I'm running the latest version of OS X Leopard and have all recent updates installed.