Thanks so much for the response; with your help I found out a lot more than I knew before. You were correct that ES was polling buttons on the wheel rather than the pedals. I can now fast-forward, rewind, and pause/play from three of the wheel buttons...which of course does not help. Oddly, in the device test screen the pedals don't do anything at all. There are 12 buttons listed, and there are ten on the wheel, each of which light up one of the buttons in the test screen...but pressing the pedals doesn't make the other two light up. Neither does anything else.
So, obviously it's not a problem with ES; Windows isn't seeing them. That seems very strange to me; I've never used the wheel on a PC before, but it works just fine on my playstation 2.
Thanks again for your help; at least now I know what's wrong. If anyone has any ideas why Windows wouldn't see the pedals, I'd love to hear.