Why download manager load file with 1kb?

Hi all,

Every time when I download installation or SP files with Download Manager (DM) , program downloads additional file with the 1kb size. For example., if I download SPAM SP ( file name KD73159.SAR) program downloads two files with the same name :

KD73159.SAR - normal size

KD73159 - 1kb (w/o file extension)

So, does anybody know, for what this file using? I know that we can delete this file and deletion does not effect to extraction proces.

DM version: 2.1.140a

regards,

Shahin