You are not going mad.
There is something very wrong there. I even had problems when I recreated the 3 circles from scratch.
The only way I could get them into Flash properly was to do them individually and they worked fine. As 3 objects on the page or a group I got the errors you experience. Even converted to editable shapes I got the errors. (as did using squares)
If - however - I drew some freehand shapes with the same fill attributes they exported to flash perfectly....well, apart from being no use at all as circles (or squares). I guess I haven't run into this because nearly all my content for Flash is hand drawn. It looks like a world of pain when I do need that functionality.

I'd say this was a bug and that you should report this to tech support. I'll cheer from the side lines and join in if I can. :-(