You probably know this but I'll say it anyway. It's important when using a roller to get a good quality roller and don't apply too much pressure when rolling out the paint. You don't want to squeeze out every last bit of paint off the roller - a light even pressure while spreading the paint and re-apply paint to the roller as needed. Also, as you're applying go at a slight diagonal over the just painted areas to help spread the paint evenly. I've painted for many years professionally and these are a couple of things that are common when streaks are evident. The others are correct - you'll have to prime it to seal out the dried streaky areas - otherwise it'll just show through no matter how you apply subsequent coats. Satins are tougher than others because they're less reflective - reflective light hides some imperfections. Good luck!
