I've got this same issue. I can print to the same printer from a different account on the same computer, so there is obviously nothing wrong with the printer or the printer sharing setup on the computer it's connected to. It must be something on my client PC - something that's magically changed since earlier today, when printing was working fine. I guess it's something to do with permissions, but why can't we have some meaningful and helpful eror messages instead of the hopeless "Error 0x00000057"?
Rowan