corsa cutting out

[shugster0]

My corsa keeps cutting out, its a corsa comfort 1.2 (2001) automatic, its done 16 thousand miles, it seems to cut out just at or after taking away from junctions, garage checked the ecu and said its either that or it might be the shift motor in the gearbox, both are really expencive: �425 for the shift motor and the ecu is �729, they said i would have to buy them both if the first thing doesnt work. its driving me nuts, exuse the pun! please help!