Thanks for the tip. Yes I am using the code examples. But the computer still hangs. After adding the Sleep function code runs a couple of times (2-3) and then when I execute it again it hangs. I am not sure if I need to physically connect and disconnect the connection to the 'GATE' pin (I tried, but no difference). I also changes the Sleep time from 100msec to 300msec, still no difference. Please help?