ls -lh show file not displaying correct size

[Wayne]

Hello,

I have a db file of FreeBSD 7.1 amd64 that is displaying the wrong size. This is a db file used by my mail filter software to to Bayes Filtering.
If I do an ls -l or ls -lh I get
filter1# ls -l
total 489024
-rw-------  1 defang  defang  274992627712 Jan 31 08:33 @@RPTN.db
filter1# ls -lh
total 489024
-rw-------  1 defang  defang   256G Jan 31 08:33 @@RPTN.db
If I do a du I gecus18-179# du
489026  .
cus18-179# du -h
478M    .
My drive is only 250 Gig and I have it mounted as /var/spool here is my df for the whole file system.
/dev/ad14s1d    226G    810M    207G     0%    /var/spool

So I know that the 256G is wrong. Can any one tell me what is up with file size ?

Thanks Wayne