Copydisk won't copy to destination disk

My Win NT 4.0 Server SP6a runs as a
Member Server. When I try to copy a floppy diskette, I get errors such as "drive in use", "disk damaged",
or "unable to copy disks on this drive" but both the source and destination disks are readable on other non-NT PCs.

Typically, I do this by using Windows Explorer, right-click on the A: drive, and select CopyDisk. It reads from
the source disk OK but once it starts to write to the destination disk I get the above errors.

This problem also occurs on other NT systems on the network. I'm also running Norton AntiVirus Corporate Edition 7.5.