Like Jazz said. Rip out all the wires and start all over again, one axis first. But before that, make a wiring diagram and start wiring when that is done and is right. Use the diagram as a guide and mark every wire you have connected. Use a multimeter to check the connection from point to point for every single wire BEFORE trying to run that axis. Don't power it up before that step.
Obviously something is wrong and you have no idea what, so I think also that it's best to start over. Just one more question. Do you use a 25 pin parallel port cable between the UC100 and the bob, or just a short ribbon cable? You could try a different cable just in case...