THERE IS A SOLUTION!
As a serving member of HM Forces (Army) and a dedicated eBayer (apparently I'm one of their stars!) I was furious that the latest revamp of the site had rendered the military community based overseas unable to use the British Forces Post Office (BFPO) postcodes.
I enquired by email as to why this change had been made and recieved the following reply from Denise Tate (eBay customer services):
"I would like to inform you that as of now eBay does not support BFPO addresses"
I did some digging and there is an answer. Simply ensure that your BFPO number is in the last line of your address. In the 'Postcode' box enter AA0 0AA. This postcode is accepted by ebaY but is not assigned to a location. The post office cannot read the postcode so they look at the next line up... and BINGO! ---> BFPO *** <---
I thank you... :O) I'll be here all tour, be sure to tip your waitress! Regards, Paul Tyler.