I don't know that I would call it "balanced". The one thing that cost all credibility with me was when former congressman Mark Foley (R-FL) was caught with this whole issue some of the former congressional aides. After three times of showing him as a Democrat, I thought that was pretty bad. I guess that's what's known as "balanced" -- call a person from one party as a member of the other party. That way you cover both parties.
That's not slanting the news. That's flat out lying.
All networks make graphical mistakes, especially on live news. When Columbia fell to earth, CNN had a graphic saying it was flying 25 times the speed of light. Also, there was that one time MSNBC misspelled "Niger"!