Oh my god that drives me crazy. I don't watch Ghost Whisper but the ads when they call her by her real name rather then character name annoy me as well.
I think it is channel 7's way of saying "Remember Jennifer Love Hewitt from the late 90's early 2000's she was a pretty big movie star for a while there and we have her on a show". Even though she is kind of a failed movie star seeing as she quit TV to concentrate on movies and is now back on TV.
Well, it's really stupid that on the ads they say jennifer love hewitt instead of the charactures name melinda. They don't do it with any other show, do they?