I'm not farmiliar with the syil kit but I'll put my 2 cents in anyway.
The X going in one direction problem sounds like an issue on the input side of the controller. Either you have miss configured Mach or you have a wiring problem. Mach generates 2 signals to move the motor, a direction signal (dir) and a move signal (step) sounds like your dir signal is not working for the X.
Does the controller connect directly to the parallel port or do you go via a breakout board. Have you triple checked the output settings in Mach match your board?
Your description of the Z axis problem was pretty vague, but keep in mind when you connect it to the control board you should have 2 pairs of wires(each going to the common) and 4 single wires connected. Again I'm guessing what the controller looks like.
Where abouts you located? I'm sure someone local wouldn't mind helping out with the wiring