The display of attributes in cart breaks my theme

Very cool concept for a module. I'm using Ubercart on an engraving website, and it'd be damned handy if customers could alter their instructions without deleting the product!

However when I enable the module the attributes extend sideways, off the screen. No doubt because I'm ignorant of theming - but also possibly caused by this module. Could you look into this?

Cheers,
John