Using ISSP program, the checksum test passed. If using MiniProg3 program, it would say "erased successful, programmed successful, verified successful, checksum failed".
Question: Does MiniProg3 use a different algorithm than ISSP's to generate checksum value?
It's not clear which device you are using. Please ensure you have the right settings under Programmer Parameters in PSoC Programmer. Can you please try regenerating the hex using PSoC Creator and programming again?
Please share a screenshot of PSoC Programmer window so that we can look at all the settings and the error.