The problem concerning every type of file (ex.: *.txt, *.xls, *.doc, etc.) and the files are all closed.
It seems to be a problem regarding the indexing of the file changing, in fact when the user creates a new file in "My Document" folder the DLO Agent check and add the file for the next scheduled backup BUT if he do the same in a folder of D:\ drive the Agent doesn't add the file in the "Pending Files".