Thanks Marco, that explains it. Not that I am happy with the restriction on editing my personal details - I think it is a serious flaw on behalf of ebay that this has taken me literally hours of phone calls to ebay and this effort here to get to the bottom of. The error I get on ebay is simply "This change can not be made at this time" but no information as to why.

Please save others from this horrible experience and make it clearer in the website form error feedback when trying to edit your personal address.

Incredibly disappointed.