As it turns out I was being blonde as to my understanding of Hugo voting/membership, so I did a swift disgorgement of funds to the correct website (this time) to unlock my voting ability.
I'm capricious with regard to swiftly disgorging funds. Impulsively decide to join Worldcon and fly to Spokane? Okay. Spend ten bucks grabbing a nominated book? Too expensive -- no!
Then I voted as previously mentioned, with the exception of substituting my vote for Elisabeth Leggett for a withdrawn nominee.
And now I've got something like 48 hours, so I might as well read the Mieville and McGuire stories too, to see if I like them enough to squeeze them onto my ballot.
EDIT: I'm reading McGuire, anyway, because there was a nice clean Mobi as opposed to the watermarked pdf of Mieville -- no thanks.