Am I correct in my understanding that you're saying the logs from one block don't align with the logs from the next block? If that's the case, depending on how far off they are I don't think I'd worry about it. Your quilt will still be lovely. If you're saying the blocks have turned out to be slightly different sizes from each other, you can just trim all down to the same size as the smallest one, and there ya go! If that makes your quilt smaller than you want it to be, just add a border. It would be helpful if we could see a picture of what you're dealing with, though I know posting a picture can be time consuming.