I've got a 1 litre, T -reg corsa breeze that keeps cutting out?

After a period of unpredictabel stuttering of my corsa, I had a new MAF sensor fitted in April and car kept running fine but soon started showing the diagnostics light again and the engine light comes sometimes on as well and on occasions the engine cuts out when slowing down before stopping. Even in the mornings when starting up the car it comes on but cuts out straight away at first before I can run it normaly. I took it back to the garage where the diagnostics computer said 'low voltage to mass air flow sensor'. The MAF sensor was replaced again under warrenty with a new one but the problem still persists. Any idea what the problem could be? The mechanic seems a bit baffled.