Well after reading this thread, I am on my second unit and both have had the screen lift as described. And to be honest, it's not that noticeable but it shouldn't be there in the first place so it's just some design or manufacturing issue.
Can I be bothered to do a fix for it, not really as there is no guarantee it won't make it worse.
So I tolerate it, think it's still a great tablet for the price and once it's in its amazon case, it'll be hidden anyway.
If I managed to help you, don't forget to thank me