I've had mine for a week and it has the same issue, also with the right side being looser than the left. However, it doesn't bother me one bit. So long has the screen stayhs up, I'm set.
I noticed the play when I first got it, and it bugged me. Now two weeks later after using it a lot (particularly using voip), I had forgotten all about the lilttle bit of play until this thread!
I had to double check on the n810, and yup it still has the play, but like Traveller, I got used to it so much that I don't notice it and had forgotten about it.