To make a long story short, I got my P550 bricked after trying to do a downgrade from wm6.1 eng crashoverhead's
to another rom: Osc260A R05_P09.nb0 .
I renamed the file ( Osc260A R05_P09.nb0) to winceimg.bin and flashed it from SD.
During reading suddenly I got a white screen so I hit reset (...