While trying to program an XC73108 with a HW-120, the programmer returns a "Product code error".
The 73108 underwent a die shrink from 1.0u to .8u. At the same time the product code was changed, because the programming voltages changed. This error occurs when using a version 3.0 or earlier algorithm.
Download the latest versions of the programming algorithms from the Xilinx Technical BBS (filename DS120ALG.ZIP).