Hi,
sorry just had a look at your Ytube post, that looks really crappy....
Some process/thread/application on your PC is causing it. A lot of threads on a PC communicate with each other using the
interrupt system and despite anything we can do Windows tends to decide on interrupt priority often at the expense of Mach3s
Pulse engine.
There used to be a list of things that you could do to your PC to improve things, I haven't seen it for a while but it helped me when
getting started. You might look in the section 'Mach3 on Vista'. Any of the suggestions there are likely to help.
If you get really frustrated the buy yourself a UC100, PMDX411 or a SmoothStepper and never look back...
Craig