The "-1" error means that the bootloader cannot find the rockbox.iriver file in the root directory or in the /.rockbox directory. You either did not install a firmware build or you did not install it correctly. Make sure that you have a file named rockbox.iriver and a folder named /.rockbox in your root directory. If not, go to the daily build page, download the most recent build, and unzip it to the root of your player.