Flash 'em loads of times, killed them, revived them, reflashed them..
You should be flashing in this order...
1. P910i_Phone_CXC162042_R4E001.AVR.flp. when attached to the phone part, disconnect and remove battery and then attach to the PDA part and flash the following in order one after the other.... you may have to lower the baud rate for these parts
That should restore your phone...