Sorry to reply after so long time. I tried to replay it, then I dd'ed a iso file into the flash disk, But it doesn't happen again, even if partprobe said :
Warning: The driver descriptor says the physical block size is 2048 bytes, but Linux says it is 512 bytes. NO ANY PROBLEM even if I choose "Ignore" always. Jessie updated its kernel to 3.16 recently, Maybe it is kernel-related... I don't know. -- Regards, C.D.Luminate