It bothered me that the AP is not displaying the Currency Rate automatically, and I do not think that this is how it should work. All the multi-currency settings are setup properly.

So, I went into the Multi-currency Sample Data and after many tests and poking around, I found what we are missing.

The Control Account screen has to be completely filled in, otherwise the Rate does not calculate automatically.

We had the "Exchange rounding error" field blank. I filled in the GL account, and now the Rates do kick in automatically.