Thanks for that, Wim. That makes sense and is something I was starting to suspect a couple of hours ago as I was waking up
It appears I may have two scripts fighting against each other: ajaxWDwx.js (an older version which I'm using for the main site proper) and ajaxWDwx3.js (which I'm using for the mobile version). I'd been hoping I could get away with that, but it looks like I can't. Oh well, back to the drawing board.