Since webadverts is EOL.
It just might be time to look for something else.
But anyway a quick google search for chmod a+w
Brings several listings to try.
But again world writable is a risk if somebody is not updating security risks.
Also if you call the banner via say a iframe then that will be broken since again the domain name has not migrated so the placement on the page probably needs to be updated via editing the html pages.
