This is what I've read, so don't take it as fact, just a possible explaination
My understanding is the original distribution studio had a deal with the production to release the movie within one year of the movies completion.
However, timing of the original release date of the movie was somewhat unfortunate. It was originally going to be released around december 2001 I believe. Of course, the nazi-like themeing of the movie, combined with the fact it dealt with topics such as depression, opression, death etc, further combined with the events of months prior, pretty much killed the release.
The studio still had to honour it's deal, and went ahead with an extremly limited release the following december (right at the end of it's one year deal). From memory, it was something like 10 cinemas USA-wide screened the movie.
I'm guessing a different publisher picked up the movie as world wide releases occured mostly in 2003.
Of course that could all be an internet conspiracy theory.
imdb lists the reasons as:
"The film was not given a wide release because it had already run into profit as a result of overseas sales, and Miramax didn't want to risk turning a money maker into a loss."
Which makes absolutly no sense what-so-ever, unless considering the possible 'conspiracy'.
It is an excellent movie imo, only let down by the fairly spectacuarly bad performance by taye diggs (??). I feel it was quite sad it didn't get a full, world wide release on the original release date.