Case sensitivity (uppercase and lowercase should not be considered unique)

I'm using this module to create book reviews submitted by members. So the title has to be unique. the problem is sometimes they don't type it correctly (uppercase and lowercase). for example, I submit a book review entitled "Siddhartha" and other user submit the same book entitled "siddhartha", unique field consider them as a different value.

is it possible to add an option for uppercase and lowercase letters? so they are considered same value.

thanks a lot, a really unique module :)