NIOS programmer for PC28F256P33BF chip

I used PC28F256P33B85 before for EP3C80 program memory, works fine, programing is no problem by NIOS programmer. but this chip is stop products now, I changed to PC28F256P33BF*, still use NIOS programmer,but give me program fault , It faild on different adress everytime. I tried many times Finally one chip program is succeed, also it's no problem for FPGA program load. but why NIOS programmer can not write PC28F256P33BF* properly.