Hokay, that's one minor mystery solved: when it comes to the missing Interzone review, the pixies got to it. Or as near as damn to. Turns out since it went so thoroughly awol in the system, they're going to hold the review back until the paperback issue of Against Gravity, which should be sometime in the late summer of 2006. Which means so far I've had precisely one - one! - print review of Against Gravity.
Paul Raven - the book's reviewer, who let me know of what happened in the first place - let me know he'll be taking his review back down soon, since it will in fact be published at some point: not quite absolute victory, but at least I gain the sense of snatching one tiny morsel of success from the slavering jaws of defeat.