Yes, it's unfortunate, as I have several FW devices that I'd like to be able to use. I'll try to connect an external drive with AC power and see if the problem was that the bus wasn't providing enough power.
Googling brought up info at insanelymac that Firewire does work for the D430, but the poster had 10.5 installed, not 10.6.
Pretty happy with the 10.6 install, which went smoothly and now runs really well. I still have to do some testing (sleep, battery), but I'm really impressed. One bonus was that the guy I bought it off on eBay said the wifi card was the original one. I was planning to install a Dell 1390, but on my first reboot the Airport icon showed full signal and I was connected! Don't know which card is installed, but it works great right out of the box.