So before you had to do some maintenance I was able to design my banner. I now get a 395005 error when trying to save my new design.
I am also getting this error. Very annoying. Can't get a response from Blizzard about it.
I was able to change my banner a couple times the first night, now I also cannot. I even tried to use a different computer of someone who is able to change their banner, just to see and it still would not work. "there was an error" I happen to not mind my current banner, but that is not the point I would love to be able to change it as its designed to be =) thanks!