Every camera I have ever owned, including 6-7 Canon DSLR's have all made a distinctively different shutter sound. Years ago I was appalled with the rowdy clunk my then new Canon 20D made after the quiet snick of the previous D60 (no not 60D).
In noise sensitive situations something I love about the 1D4 is the option of the "silent" shutter option. It's not silent of course, but spreads the sound out over a longer period. Not exactly sure how this achieved, someone may post how it's done, but it is FAR less obtrusive than the regular release sound.
No, there is nothing wrong with your excellent new camera. You won't even notice it after a day or so.