The first 27 and the 10 last frames are black?

I’m learning simple animation, and is stumbled across a problem I have no idea why is happening. My animation is 350 frames long, and when it rendered I diddnt notice anything unusual. But with the finished result the start of the sequence is all black. After checking I see that the first 27 frames are black, and after that everything is fine. I cant find any misplaced keyframes on any objects or anything, but i have no idea where to look for something that I’ve done wrong.
I still cant render the first 27 frames, even if I try one at the time. But the 28th frame is all fine and dandy…

Any ideas to where I’ve messed up?

Hmm, just noticed that the last 10 frames are black as well???