no y axis

Hi all
I have been reading all the messages I can, but have hit a snag
I have made the dro card that tom & dan have worked on, and it
worked real well until last week, it would not read the y axis
all others will work. so I made another card and installed it in
my 386 computer on the mill no luck. so I put it on a 486 computer
still no y axis reading. I don't know what made me do it, but I put
the 3.5 floppy disk in and ran the file txt_dro.exe, and it will work.
but not from the hard-drive, only from the 3.5 floppy.
has anyone had this problem before Thanks for any help
Jim (hexbolt)