[Raindrops theme] Page width broken

Ok, about 3 theme updates ago the option for Page width 100% fluid broke. As it, its only 100%/fluid for the full size of the browser window up to a certain size, and then after that point it left justifies with a huge gap on the right hand side of the screen. This has been DRIVING ME NUTS. And no playing around with the settings has solved the problem. I assume somewhere in the code is a “max-width” that I’ve not found yet that is limiting the size.

Can someone point me to the appropriate place in the code? Or at least give me a hint as to the appropriate code to override that max-width? I’m not sure coming up with the code is possible till I know where in the code it is, but its driving me nuts…..