The XC9536xv is not properly programmed if the Verify option is not selected when the device is programmed. iMPACT reports "Programming Successful", but errors appear in the _impact.log file.
When programming the device, select the Verify option, as well as the Erase and Program options from the Programming options menu. Xilinx recommends selecting these options when programming CPLD or PROM devices.
This issue will be fixed in the next major release of the software.