MCF8316AEVM:Problems connecting to the GUI

Hi group. I bought the MCF8316EVM board from TI. At first the board connected very well with GUI version 1.1.8. after i read the MPET the parameters and i write to the EEPROM then power off the VM. When I power it back on, the board still connects to the GUI, the D6 light blinks slowly, but just clicking to read the registers shows a connection problem. the D6 light is off but I can still turn the motor by turning the potentiometer counterclockwise. please help, thanks