Danno,
My optional insurance is in fact for international insurance. I am using USPS priority mail shipping method. I am sorry but I don't understand the Cal'ed term you use above.
I would of thought that eBay would revert back to the standard USPS insurance rates for the basic insurance but that does not seam to be the case. Right now I am getting $1.70 for shipping to Canada but shipping to the UK comes in at $2.45 for the same item. The $1.70 seems correct based on the cost of the item.