Freeldr installation on floppy disk from Ros

The installation of freeldr on floppy disk is working correctly under Windows XP
but but fails if is made from Reactos :

• From Freeldr\install directory , Run "install a: fat"
• The following messages are displayed :
  Opening volume "a:"
  Volume c:89 : SetFilePointer () failed - Error code 1
  Volume C:89 ........ Error code 1
  You must now copt freeldr.sys and freeldr.ini to a:

A "Dir a:" command shows that the bootsect.000 file has a size of 0 byte instead
of 512 bytes.