The jailbreak procedure you tried was for FW 5.6.5 only. Did your upgrade complete? What firmware version did it have BEFORE the upgrade? At this point, you might be limited to jailbreaking it by attaching wires to the internal serial port (as
knc1 said, referring to
this thread) -- not for the timid, but not difficult if you have any soldering experience (and some have used pins and tape and foam instead, to attach to the serial port pads).