Thanks for the reply. My payment and collection addresses have been updated, and I cancelled the one bid and ended the listing. But when I create a new listing it still shows the old address; I've checked all the addresses set up in here https://accountsettings.ebay.co.uk/uas/addresses and none now reference my old address so I am at a loss what to do next.

Is there a significant delay between amending the address and the new address showing on a new listing, perhaps?