New Spartan 3 Board: Wrong ID Code retuned ?

Hi Group

Sorry im writting in English, but my written German is not good enought 
for explaning my problem, but please answer in German reading no
problem :-)

I have developed my own Xilinx SPARTAN3-400 board but have a problem 
when trying to connected via JTAG to the FPGA, i am using the USB Cable 
from Xilinx but with out luck.

There is only one FPGA in the chain, i have rechecked power sequencing, 
and recehecked the connection to the FPGA JTAG/POWER/Ect.

The ID code i can read from the spartan via Chain debug in Impact:
00000000000001111000011110111111

I have tested when a eval board from memec with the same FPGA which 
returns:
00000001010000011100000010010011

I really dont have any ideas more whould could be the problem, are there
somebody how can give me a hint to would me could be te problem ?

Thanks a lot in advance

Best regards
René