You might want to try XFS or something to mount the disk as a virtual floppy, then use a OS supported nibbler to copy that file to dfx: (aka real floppy disk).
http://aminet.net/package/disk/misc/xfsMaybe flash copy
http://aminet.net/package/disk/misc/FlashCopyI haven't tried this before but it might work.
I have also read
"EADF is missing the additional information needed for this, e.g. missing definition of the proper track splice point etc. EADF also does not support density changes, something used pretty often"
So it might be that the disk just does not have the information to be written back to disk properly.
EADF is the ADF format that supports long tracks.
Source :
http://forum.kryoflux.com/viewtopic.php?t=627
