Now when you turn it on, have no USB devices other than your iPod connected. Press the Power button, then immediately press Eject. PSJailbreak will then load and you'll see the Install Package Files icon on the XMB.
Manager2 will NOT work because it uses Hermes payload. The source says that this uses the original PSGroove payload.
The original PSGroove did not have backup manager support (you could install it, but not play any backups). Is this why I can't get any backups to load?
Once you load up Rockbox after changing the rockbox.ipod file, either flick off the power switch (Phat), or unplug from power (Slim) on your PS3, then connect your iPod using a USB cable, now return power back to your PS3.