Well, on Sunday, we were out for the afternoon, and when we came back, after a short while, Anna noticed her skulking around under the desk again, and yep, she'd had a wee in the same spot again.
My instant guess is it's a psychological issue, rather than a physical/medical one, but we'll see. It seems that both times she's done it, we've been out for 5+ hours, and she's had a wee pretty soon after we've come home.
I'd read something years ago about feeding a cat where it's weeing, as they never do bodily functions where they eat. Seems plausible, so for now at least, she's geting fed next to her wee-spot, and we've been about 18 hours with out an issue! :-) Do you think that proves anything? :-)
13 hours ago