Flashing at 8250 and 8210

I'm using a rolis flasher and a dejan dongle

I have a customize flash file for 8250 that i backup from another phone that working(100%)

After i backup the flash file and i use knok for checksum and i getting error but rolis didn't show any error.
I try to use knok to fix the problem by using "Checksum and Fix" but i receive error "mobile not prepare" at some of the address...

I try to flash at my phone....i update FAID ,change IMEI and Open SP with NK_CAL

i can see the network but don't have signal after a while the phone will restart itself
(I can flash 3310 to 3315(customise version) working 100%)

May i know what is the problem?Software!!!hardware!!!cable!!! dongle!!!
Is there any solution that i can backup the flash error free?

Thank guyz........