A Verify failure occurs in iMPACT 9.2 sp1 and earlier when the "Program Flash and Load FPGA" operation is performed on a Spartan-3AN device if the internal PROM's "Power of 2" Binary Page Size option is set. The operation works if this option is not set.
The PROM internal to the Spartan-3AN can be set to operate in a special addressing mode. This mode changes the way data is accessed for programming and read back. The method that checks for this situation and updates the algorithm behavior is not called when programming the Spartan-3AN, as it should be.
This is fixed in iMPACT 9.2 Service Pack 2.