I am only using the core banner component of Joomla 3, so why should it break that, if the image is set to 728x90?It's just a matter of html and css / the way your template is coded.
So what can be done?If you have access to your template code (you can modify the template code), you can try to modify this part below :
Your couch. It is mine.
I'm a cool paragraph that lives inside of an even cooler modal. Wins!×