... are you saving the files? How is the floppy disk formatted? Do you get a confirmation that the files is actually saved? Have you tried to reload the file from where you first saved it to verify that it is on the disk? Is the read/write protection tab on the floppy set correctly?
Also, in DOS format, (non windows) have you done:
cd\A: (change to A drive)
A:dir (get a listing of all files on the floppy disk)
If the files show up, then check the file size and make sure it seems reasonable for the file you saved...
(ie. 1K file size might not be right, so the data might not be there. 750K might be right, so the mile most likely has daya. I used these numbers as arbitrary examples of comparison... I have never checked a G-Code file fo ractual size...)
If the files did not save, reformat the floppy and re-save the file(s) and verify them again as above. If they are there, try running the program. If they are not there, try another floppy.