I don't think there's a legitimate notable or scandalous reason it bombed. It simply didn't appeal to audiences. I did hear the production ended up coming in dramatically over budget, so that didn't help, but even if it hadn't, its box office numbers still would have been found lacking. You could blame the lackluster marketing, the aesthetic of the movie, the lack of "name" actors or any number of factors. I remember not expecting it to be very good going in for whatever reason, maybe because it looked kinda cheesy or low-budget. But I was pleasantly surprised as it turned out to be a very strong adaptation, even if Jeremy Sumpter was kinda weak in the lead role, imo.
EDIT: Oh yeah, and it was the week after Return of the King, lol. Other openers that Christmas weekend were Cheaper By the Dozen and Cold Mountain, all of which outperformed it significantly. Christmas releases can be brutal. We've got another fairly crowded one coming up, I believe, and something's probably gonna bomb there.