scripts not found, but they are there!!

Hello, I encounter the problem that if I put my scripts into a directory without internet user, the scripts won't be found, but the php parser is launched, because the message is not "404 Url not found" whileinstead it is "Warning: failed to open... No input file specified" So, the user that access the directory where my scripts are, can execute php... but files are weirdly not found... and they are there!! Any help appreciated. Thanks Nicola Delbono