Thanks for replying. I don't mind the rivers, I just want the text to be uniformly justified. Unfortunately I already did update the software. I hoped, in vain, that it would correct the issue.
What annoys me even more is that even the books that I downloaded from Amazon, have this problem. Parts of it are correctly justified, other parts are left-aligned, some times just a few lines per page will be left-aligned, or justified for that matter.
I wonder if it might be my actual unit that is defected?!