Shiggs, no worries, we'll get 'em :)
My point plain and simple:
a) Vampire canNOT be turned into zombies since they are already dead and are immune to everything BUT things listed above.
b) Throw a couple of nukes and all zombies are wiped out. All vampires will need is keep enough clean livestock (humans) to procreate and that's all - war ended :)
I guess we have to settle first if a Vampire can turned into a Zombie or not. The problem is that the retrovirus that turn a human into a vampire (HMHVV-BL (the Bruckner-Langer strain)) is from the same base virus that turn a human into a Zombie or Ghul (HMHVV, Krieger (the Krieger strain)).
Since you can fall prey to several virus infections of the same base strain it'd say it's a given that a Zombie can turn a Vampire into a Zompire.
Though this is just the common metavirus that occures naturally. It stands to discuss what happens with combinations of human made Virus strains like the Umbrella T-Series). I can not say how this strain will affect a Vampire upon infection.
^^ I think it's fair to ask for references for the above information.