[olug] How to force internal HDD to be sda?

[Kevin D. Snodgrass]

I have 2 external hard drive cases that I use extensively.  On my laptop (mostly), in Fedora 13 if I boot with the external drive plugged in via USB it gets assigned /dev/sda and the laptop internal drive gets assigned /dev/sdb.  When the external is not attached the internal gets assigned /dev/sda.  Why?  Sorry to be blunt, but that is just damn stupid.  (Says the crusty old UNIX guy)

Is there some way I can force whatever is doing this (I'm guessing udev, since this problem starting showing up with it's introduction) to assign the internal to /dev/sda?

Kevin D. Snodgrass