AceShowbiz -

Miley Cyrus may not be able to write her boyfriend Patrick Schwarzenegger's name correctly if she is asked to. It's his last name that she has trouble spelling. "Literally, I just had this conversation, I can't tell you," she said on "Good Morning America". "Apparently there's not a T in it."

She visited the ABC morning show to promote her new MAC Cosmetics Viva Glam campaign. The proceeds from the sale of her custom lipstick will benefit the MAC AIDS fund. "It's fun for young people to get to buy a lipstick and know that it's going to actually go to changing the way that their future is going to be," she said.

The "Wrecking Ball" hitmaker added, "I realized that if there's going to be all this attention on me all the time, no matter what I say, no matter what I do, I should be saying something and speaking on behalf of those that kind of feel like they have no voice."

She also defended herself against critics, insisting that she was wrongly portrayed in the media. "I'm not the way that people try to make me seem ... I don't go around just trashing hotel rooms and partying, that I'm actually working on, you know, music that I love and being involved in things that I love," she explained.