Problema flashtool

[goker]

Hola compañeros, les cuento mi problema queria cambiar mi stock que es la ..42 a la .62 y al momento de flashear me marca esto ya intente flashear de nuevo la .42 y sigue igual alguien sabe q puedo hacer?

23/056/2012 22:56:33 - INFO - <- This level is successfully initialized
23/056/2012 22:56:33 - INFO - Flashtool Version 0.6.8.0 built on 2012-02-26 19:26:25
23/056/2012 22:56:33 - INFO - You can drag and drop ftf files here to start flashing them
23/056/2012 22:56:38 - INFO - Device disconnected
23/056/2012 22:56:43 - INFO - Selected R800a_4.0.2.A.0.42_Firmware Gene¦ürico Latinoame¦ürica.ftf
23/056/2012 22:56:43 - INFO - Preparing files for flashing
23/056/2012 22:56:47 - INFO - Please connect your device into flashmode.
23/057/2012 22:57:39 - INFO - Device connected in flash mode
23/057/2012 22:57:39 - INFO - Opening device for R/W
23/057/2012 22:57:40 - INFO - Reading device information
23/057/2012 22:57:40 - INFO - Phone ready for flashmode operations.
23/057/2012 22:57:40 - INFO - Start Flashing
23/057/2012 22:57:40 - INFO - Flashing loader
23/057/2012 22:57:42 - INFO - Loader version : R4A066 / Bootloader status : ROOTED
23/057/2012 22:57:42 - INFO - Flashing adsp.sin
23/057/2012 22:57:42 - ERROR - ERR_SEVERITY="MAJOR";ERR_CLASS="SECURITY_CLASS";ERR_STATIC="SIN_HEAD_VER";ERR_DYNAMIC="Failed to verify sin header";
23/057/2012 22:57:42 - ERROR - Error flashing. Aborted
23/057/2012 22:57:43 - INFO - Device connected in flash mode
23/057/2012 22:57:44 - INFO - Device disconnected
23/057/2012 22:57:45 - INFO - Device connected in flash mode