It's probably not the cables but rather the protocols that are installed on each machine which carry the traffic.  Which protocols are installed on the ones that work as opposed to the ones that don't work.  You need an additional protocol to communicate with a Novell system.

No Im not sure you understand, I can take a new dell out of the box and set it up at my desk and move it to a desk 5 feet away where the only difference is the cable and I wont be able to see the network or login. I usually have to try different cables until I find one that works.. it is a real pain inthe but.

I undersatnd completely, in order to connect to a Novel netwrok,  you need the NW Link IPX/SPX protocol added and no Dell machine would come that installed.