If I get any further ideas, I'll let you know; but for now I don't have any. I have heard of this happening to exactly one other person with a set of scripts, though I don't remember which set. I've also had this problem
on one NVDA project, where NVDA refused to load the add-on for an application. It's a rather frustrating problem of course, because until the screen reader loads my code, I sort of don't have much I can do.