About "Highlighting same words"

Hi!

It's very useful for me. Thanks for this brilliant app!
But i want to say a few words about "Same words highlighting"
This function does not work as we expected. It reacts to capital letters, and this should not happen. "Ball" and "ball" are the same word, but because of the capital letter "C" the system thinks that these are different words.
Please fix it. 
Thank you - U are the best!