Neptune,
OK. It sounds like you should update U-Boot anyway. Here is a post where vlad successfully installed U-boot using Jeff's script (this is an older version of U-boot, but should work and revive your box). After you've done this, boot with Arch rootfs.
http://forum.doozan.com/read.php?3,6965,9111#msg-9111
Warning: updating U-boot always has some risk of bricking. Using Jeff's script, the risk is very small (eg. things like power outage). If you see anything strange going on during the script is running, don't reboot and post the entire log of what's going on here so we can help. The GoFlex Net can be unbricked with serial console if needed.
OK. It sounds like you should update U-Boot anyway. Here is a post where vlad successfully installed U-boot using Jeff's script (this is an older version of U-boot, but should work and revive your box). After you've done this, boot with Arch rootfs.
http://forum.doozan.com/read.php?3,6965,9111#msg-9111
Warning: updating U-boot always has some risk of bricking. Using Jeff's script, the risk is very small (eg. things like power outage). If you see anything strange going on during the script is running, don't reboot and post the entire log of what's going on here so we can help. The GoFlex Net can be unbricked with serial console if needed.