Hi I’ve just installed waipuoa theme I don’t…

Hi, I’ve just installed waipuoa theme.

I don’t know why, but it happens a strange thing in some blog posts:

in the firts lines the letters are smaller the in the other lines. Why?

How I can avoid it?

you can see an example of my problem at this link http://www.davidemorante.it/2015/04/le-lettere-accentate-maiuscole-e-i-caratteri-speciali/