ALFA 1.8 ENGINE HEAD ISSUES?

[BIG DUNC]

A good freind of mine ( actualy my Mum's boyfriend ) has a 156 1.8 twinspark.
Its W reg ( year 2000 ) and he has had it from new. All servicing / repairs etc have been done by the local Alfa dealer he originaly bought it from. Its just passed 100k miles. Service history ( from Alfa dealer ) is 100% complete.
This cyl head has been off this car three times now. The first time it was nearly new, so paid for by Alfa.
The other two occasions, it has cost him well over £2k each time. I don't know the exact details since he is not really a car person, and just goes by what the garage sais.
However, is this a known fault, and if so, what is the long term answer?
Or, has he been really unlucky?
This is not a "slagging off Alfa" post, I just want to know how to stop it happening again, or should he sell it before it happens again?

[Avocet]

Haven't a clue! Does he say WHY it was off? Is it the same reason each time? As far as I'm aware, the heads themselves aren't troublesome but the cam belts are and if they break, the head needs to come off to repair the wreckage. I guess it also MIGHT be possible that a bad enough cam belt failure could damage a head and that if it went unnoticed, it might have to come off again subsequently.

[BIG DUNC]

I don't think the cam belt failed.
When I asked why, he was a bit vague. I don't THINK it has been the same problem 3 times, but 3 different problems is still a worry!