Q:  I have downloaded the voyetra midi software, which I believe is a great
    software, so far. But I have encountered a problem after a while of using 
    it the software stops it. there is not way you may move the mouse, and the
    letters and numbers on screen chance in parameters (larger or smaller). 
    I can only use the keyboard, to save what I have done so far. I wonder, 
    if is a problem of the demo software or there is any solution to this
    problem. 

A: The problem you are having is system related. It doesn't have anything to 
   do with the fact thats it's a demo.

   Try the following:

   1. Try downloading and installing the latest drivers for your video card.
      If it came pre-built inside your computer, you should be able to find 
      the drivers at your computer manufacturer's website.

      If you installed it yourself, you can find the drivers at the card 
      manufacturer's website.

   2. Make sure that if you have gfx drivers or something similar, 
      that you turn down/off the hardware acceleration:
      (Start->Settings->Control Panel->Display->Settings->Advanced 
      Properties->Performance).

__________________________________________________________________________