RCM6700 , VBAT & FAT

Hi all 

I have a problem with RCM6700 and the fat16 filesystem.
I have 3 files, exactly :

#define FAT_BLOCK
#use "fat16.lib"
#include <errno.h>

FATfile data_file;
FATfile log_file;
FATfile init_file;

fat_part *first_part;

All the file operations are with fat_Xxxx (fat_Open(...) etc) commands and the filesystem is mounted with the automount USE_FEFAULTS routine.

Well, when the backup battery is mounted you leave the device unplugged from power and the files and the data are there.
If you unplug the device without a battery and after you plug it again
all the files are erased. The partition is blank.
The question is how we can tell to RCM to put the files in the flash 
or if they are in flash (as I thought) the static ram holds some informations about these files ?

Thank's in advance

Akis