Yes... it looks like something is breaking your installation of nUI. It could be a couple of things... either another mod/artifact that is interfering, or a font problem.
First, I would *strongly* recommend you do a clean installation as per the instructions in this FAQ:
http://www.wowinterface.com/forums/s...ad.php?t=37330
Second, locate the font
FZLBJW.TTF and place it in your [
World of Warcraft > Fonts ] folder
Between those two things, it should get you up and running.