Can a particular network card be permenantly bound to an eth'x' number?

[rich <stantonrj@cf.ac.uk>]

I have several network cards in my laptop - wired lan, wireless lan,
loopback & firewire.  After a recent update (I'm running testing) my
interface numbers all jumped around so that instead of the wired lan
being eth0, it's now eth1 & the firewire is eth0.  What defines what
eth'x' number is given to which network device?  It's a pain having to
change configuration each time they move numbers (as also happens
depending on whether I boot with my wireless cardbus in the slot or
not)!