The ECU flash does not solve the cutting out problem, it solves the problem of the CEL being lit after the PSAI system has been removed under recall. Both of you have had the recall performed, most everyone has, and therefore you got the flash at the same time.

The problem the original poster is describing is a factory defect in the ECU. It is a circuit board construction problem. You need a new ECU. I already posted a link where you can buy them.