The ground (work) goes in the 6010 port. There should be a little diagram on the machine above the ports that shows this. Just checked - there is a "-" sign between the two "-" ports.
If you put the stinger in the 6010 port and the ground in the "-" port then both leads will be grounded and you'll get nothing.
If the stinger is put in the 6010 port and the ground in the usual stinger terminal (there should be a big "+" sign above it) then you have straight polarity. (DCEN, DCSP) The machine can be used this way for shallow penetration or hardfacing.
I'd recommend leaving the 6010 port for the ground when using DCEP and 6010 rod.
If using DCEN put the stinger in the unmarked "-" terminal. The 6010 port is set up for a specific set of circumstances and there is no reason to screw with it. Mark from Everlast can elaborate.