DFU clock and custom made board

[Nomi]

I am using nrf51422 sdk v8.0 on pca10028 kit and softdevice s110. My DFU and custom made application works fine when i use clock SOFTDEVICE_HANDLER_APPSH_INIT(NRF_CLOCK_LFCLKSRC_XTAL_20_PPM, true). Then i transferred my codes to my custom made board but all codes work there when i change clock to SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_RC_250_PPM_TEMP_4000MS_CALIBRATION , NULL). But now i want to add DFU to my custom board. i changed the clock to SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_RC_250_PPM_TEMP_4000MS_CALIBRATION , NULL). in dfu_dual_bank_ble_s110_pca10028 an example project from keil packs. dfu advertise nicely but when i try to upload my application there comes an error "the connection has been lost". Can someone point the error is it because of clocks or something wrong in my code.?

[Nomi]

sorry it isnt SOFTDEVICE_HANDLER_APPSH_INIT. I used SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_XTAL_20_PPM, NULL); . The clock already used in dfu_dual_bank_ble_s110_pca10028 example. But on my custom board my codes work when i change clock to SOFTDEVICE_HANDLER_INIT(NRF_CLOCK_LFCLKSRC_RC_250_PPM_TEMP_4000MS_CALIBRATION , NULL). Now when i change clock in pca10028 dfu does not work.