4000GB partition becoming 1801GB after reboot?

[Isolationism]

I'm in a bit of a pickle; I created a nice shiny new 4000GB partition in
parted 1.8.8 (on gentoo, kernel 2.6.19) a few weeks ago and started piling on
the data. After an unexpected reboot due to a pulled power cord, the XFS
partition not only refuses to mount, but completely fails to repair as well.

After pulling my hair out with xfsprogs for the better part of the day, I
checked the partition in parted, and discovered something has gone horribly
wrong: The disc is still detected as being 4000GB, but the primary partition
size is now being reported as 1801GB. The result of printing the partition
table looks like this:


Model: AMCC 9550SX-12M DISK (scsi)
Disk /dev/sdb: 4000GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos

Number  Start   End     Size    Type     File system  Flags
 1      32.3kB  1801GB  1801GB  primary  xfs

(Another smaller 1600GB partition on the same controller shows up fine).

I really don't know what I'm doing here, but I am afraid this is going to
have to do with some 2TB limit thing, although I'm not sure why if I was able
to create the 4000GB partition the first time around.

I would really, desperately like to be able to somehow recover the contents
of the partition, but this looks pretty grim. Is there any way to restore the
partition to its original, correct size -- even if only temporarily, so that
the data can be rescued -- without obliterating all of the data from the
device? Any help would be very greatly appreciated.

Cheers,
Kevin W.