XFS, empty files after a crash

[kfx]

Hi,

After a crash, a lot of files on a xfs file system report an empty size 
with "ls -a" but not with "du".
xfs_check and xfs_repair don't report any problem to repair (although an 
internal log is used) :(
So if I understand correctly, those empty files actually use space on 
the disk but are incorrectly reported as empty by the system.
Is there a way to copy back the used blocks to recover the files ?

Example for a previously not empty file:
# ls -l myfile
-rw-r--r-- 1 me me 0 2012-01-24 15:29 myfile

# du  myfile
27460    myfile

# du --apparent-size myfile
0    myfile

# xfs_bmap myfile
myfile: no extents

System: Ubuntu 11.04  2.6.38-8-server x86_64

xfs_info /dev/sdc1
meta-data=/dev/sdc1              isize=256    agcount=10, 
agsize=268435328 blks
          =                       sectsz=512   attr=2
data     =                       bsize=4096   blocks=2441215488, imaxpct=5
          =                       sunit=128    swidth=640 blks
naming   =version 2              bsize=4096   ascii-ci=0
log      =internal               bsize=4096   blocks=521728, version=2
          =                       sectsz=512   sunit=8 blks, lazy-count=1
realtime =none                   extsz=4096   blocks=0, rtextents=0

Thank you