Do You Finish A Book When You Hate It?

My coworker and I have had this conversation dozens of times.  We make our living with books.  We both work in an elementary school library. I am the Media Specialist. She is my assistant and my right arm. (I'd be lost without her.) We are both avid readers.  We LOVE books. But- what if you start reading a book and suddenly realize , well....it sucks. Do you finish it?
This has happened to me twice in one week.  The first was an actual Newberry Award winner. I wanted to love it. I tried to love it. But... well, every time I picked it up it was with a sigh...more of the same. It was insanely boring to me. Notice I said to me. Obviously it was great to someone. (Lots of someones) But not to me. Finally I said, "I can't do this. I really hate this book." Her reply? "Girl, I never got past chapter three!"
The same happened with an adult fiction book.  I started it one week ago. It had promise. Great plot. But as the week wore on...well, let's just say I didn't sit up at night waiting to see what happened next. Earlier today I had to face the facts- I dont' give a rat's ass what happens next. (Sorry.)  What started out as an amazing book is now bogged down in a mire of endless, needless detail. I've given up on what happens next. There is no next- just more of the same, same, same...
So, what do you do with a book you hate? Do you optimistically keep reading, hoping it will pick up it's original momentum? Or do you give up and move on to better books?
 I won't review either of these books. I can't. I'm a witter. I know how much of a writer's heart and soul goes into his/ her writing. See my review policy. If I absolutely hate it I won't review it. Maybe the book is great. Maybe the problem is me.
So..what do you do with a book you hate?
I'd love to know? Can't wait to see your comments.
Happy Sunday
Beth :o)