You're telling me what designers do as if I'm not one. It may help if you stop talking down to me, and put that effort toward clarifying your message.
May I say from the outset that this comment is very rude, unnecessary and detrimental to your cause. Acorn is trying his best to answer your problem and in no way is he "talking down" to you. Let's stay civilised.

I can see this problem within FF but not other browsers. I suggest it's more to do with the call to paypal on the roll-over effect than it is to do with Xara's software. What happens if you also call the paypal purchase button within the mouseoff state?