Unless you own the company or are a partner, never imagine you're anything other than work for hire. The worst part is if you're a good soldier and do your (unpaid) OT, there's no guarantee you'll see any kind of reward. Employers who mandate 40+ weeks are ususally the kind who are looking to screw their employees any way they can. It is, however, a perfect sign that you need to be looking for a new job immediately.
I would loath to work for a place where I were just "work for hire". Case in point: I was laid off at the last place I worked. My direct manager explained the situation personally, apologized profusely. And then acted as a reference for my next job. Sure, I lost my job, but I wasn't just dropped like a used tool.
