Test from the command line of one of the PC's (Not one you are setting up)
If it works in the commandline but not the printer it is the firmware, but I highly doubt that since it works to existing users, just not the new ones.
Trying to set up new users using FTP through Win7... I have the Windows software apps installed, (FTP, etc) but when I try to scan to the folder, the machine reports "Job Deleted: Log In Error"
I have it set up the exact same way as every other location in my office, and there is no password set on the destination folder. I'm stumped.....