I have problem with fonts in GTK applications in Kubuntu 14.04 (problem was in 13.10 too).
Some characters are rendered by another font. Problem is with all GTK applications. Problem is with all local character and with some other characters like E or D.
Problem is not with settings in
gtkrc file. I tried with this file everything.
I tried to create a new user and this new user has the same problem with fonts in GTK. Qt application are ok.