I have been trying to program the demo code supplied with the Coolrunner 2C256 Demo Board with no success. I am using a Zilinx Platform Cable USB II programmer with Impact 12.1 on a Linux system which I have been using to program my S3E boards successfully. I have all the sires connected ecept HALT and am using the external transformer power supply made for the demo board. The green light on the Programmer lights when I apply power but fails to program. Help please?