deneb has actually three ports, two internal to connect with a cable extension to a free rear expansion slot. and one external mounted directly on the pcb. you have to be very careful to connect the cables right way around, otherwise you might fry your deneb. also be careful with the external port, while you cant misconnect the cable it is quite fragile, you should place much pressure on it.
you can download current version of poseidon (4.4) right here:
http://www.platon42.de/index2.htmlthe instalation is well documented and automated. read the guide.
while at it you can download the last firmware for your deneb:
http://www.e3b.de/usb/firm/DENEB_V11.lzhcheck what version you have before the upgrade.
what concerns the jumper. i dont know what you mean. jumper is jumper, usually they are found laying around.
i can get you more extensive help when im back with my hardware.