Problem with searches - part II

Hi,
 
The next step in my problem with searches is that the ".fnm" file that I
need is not in the folder it should be, and Jahia returns the "A file or
directory in the path name does not exist." error, but in the folder, I can
find the same filename but with a different extension: ".del".
 
I can´t force the re-indexation of the site because I get the same "file not
found" error.
 
Does anybody know the solution to this problem? Would be a good idea to
change the extension of the file to fnm?
 
Thanks in advance.