por si sirve de algo:
05/040/2012 02:40:08 - INFO - <- This level is successfully initialized
05/040/2012 02:40:08 - INFO - Flashtool Version 0.6.9.1 built on 2012-04-09 19:22:19
05/040/2012 02:40:08 - INFO - You can drag and drop ftf files here to start flashing them
05/040/2012 02:40:13 - INFO - Device disconnected
05/040/2012 02:40:19 - INFO - Selected XperiaU_ICS4.0.4_nu.ftf
05/040/2012 02:40:19 - INFO - Preparing files for flashing
05/040/2012 02:40:38 - INFO - Please connect your device into flashmode.
05/041/2012 02:41:01 - INFO - Device connected in flash mode
05/041/2012 02:41:01 - INFO - Opening device for R/W
05/041/2012 02:41:01 - INFO - Reading device information
05/041/2012 02:41:01 - INFO - Phone ready for flashmode operations.
05/041/2012 02:41:01 - INFO - Start Flashing
05/041/2012 02:41:01 - INFO - Flashing loader
05/041/2012 02:41:02 - INFO - Loader : null - Version : R5E006 / Bootloader status : NOT_ROOTABLE
05/041/2012 02:41:02 - INFO - Flashing kernel.sin
05/041/2012 02:41:04 - INFO - Flashing fotakernel.sin
05/041/2012 02:41:06 - INFO - Flashing modemfs.sin
05/041/2012 02:41:07 - INFO - Flashing partition-image.sin
05/041/2012 02:41:08 - INFO - Ending flash session
05/041/2012 02:41:08 - ERROR - ERR_SEVERITY="MAJOR";ERR_CODE="0076";ERR_DYNAMIC=" failed to set ta config";
05/041/2012 02:41:08 - ERROR - Error flashing. Aborted
05/041/2012 02:41:08 - INFO - Device connected in flash mode
05/041/2012 02:41:09 - INFO - Device disconnected