THank you, RosaBud. I keep hearing all this stuff tossed about with the song crediting in the album and whatnot. POint is this: when a singer is dubbed for one song, they're not going to mention it. In fact, it's very likely they'll do their best to hide it because they don't want that kind of information out about their star.
I again point you to the Marni Nixon years. She was never credited for all of that singing in My Fair Lady and even West Side Story. IT got out, of course, as these things do, but even so, the knowledge that she dubbed a lot of Anita's singing didn't come out until not long ago.
So these things are easily buried. When the only people who know are studio people in the recording room and Dale Kristien herself, plus it's Phantom, which, I must frankly say, isn't the most anticipated movie of the season, so it's not like people are scrounging around for scoop.
I still maintain she was dubbed.