Engine Management light...MAF problem?

Hi,
A couple opf weeks ago the engine management light came up on the dash of my 2001 1.8T A6 Avant. It had already been booked in for its MOT so I asked the garage to check it out while they were doing the MOT. They reported that it was to do with the air sensor detecting an incorrect flow. They put the car through the MOT test and it passed the emissions test with flying colours. They switched the fault light off and told me to keep an eye on it.
The light came back on again yesterday, so I have contacted the garage to get it booked back in (as they said they woud sort it for free). On both occassions there has been no loss of power or anything else that is noticbly different from normal.
Does this sound lke the MAF needs to be changed?

Thanks
Kev.