One more idea, even though it seems unlikely to me. Make sure that the dr800+.sh file is executable. In windows this is not done the same way it is in linux, so check this using "rxvt" on your DR800 by going to "_dr800+" folder and typing "ls -l" (no quotes). The first column in the list will be the permissions column and should read "-rwxr-xr-x" (no quotes). If it's not then set the permissions using the command "chmod 755 dr800+.sh" (no quotes).
Then run the command again and see what response you get.