Watch closely for the part where Jack prepare to meet Rose's family at the party. In front of the room is a glass door. If you pause there and look closely at the glass door, you will see a cameraman and his camera!!
I noticed it too. I've seen camera men reflected in a lot of movies though, so it's not a big deal really. Plus--one of my friends dad's work in the movies and they said it's somewhat difficult to get reflections out of things.
Okay, no offense, but its kinda sad that you actually looked for that. Plus, you cant always not have a reflection. If the camera was in a different place, it wouldnt have had the same effect on the scene, and if they got rid of the door, then it wouldnt be true to the titanic. you gotta compromise sometimes.