If you lock yourself out of your steelhead box (tested on 4.0 or later), you can recover the password much like a router:
Get Console access.
Boot the appliance (or reboot)
When you see the word grub immediately press E.
Another GRUB menu appears, with options similar to these:
0: root (hd0,1)
1: kernel /vmlinuz ro root=/dev/sda5 console=tty0 console=ttyS0,9600n8
select the line with kernel in it using up and down arrow keys
Press E to edit the kernel boot parameters.
Append " single fastboot" at the end of this line. Note the space before 'single', it is very important. (And do not enter the quotes.). Press Enter.
Press the B key to continue booting.
After the system starts, at the command prompt, type "/sbin/resetpw.sh" and press Enter.
The password will be blank.
Type "reboot" and press Enter to reboot the appliance.