device signature error!P89c61x2BA

[qingdao_569]

When i used FM to programme my MCU "P89C61X2BA 1G3010 AtG0603G",it issued a hint  that "The device signature does not match the expected values.Accessing a device using the wrong protocol could render the device unusable.Do you want to countinue?"Then i read the signature by FM and the siganture is "Manufacture ID :0x15.Device ID1 :0xc2 Device ID2 :0x82 ".Whats the problem?
Also when i selected the device "P89C61X2" from the up-down list there was a warning "Please ensure the device you have chosen matches your actual device.Attempting to use this device selection with a different device could result in inability to reprogramme it via ISP.The only remedy will be to use a parallel programmer to erase the device. "Why?