If what you are saying is that your belt has slipped 3 times in the last 2 months, you may have a variation on the tensioner spring pictured below;
http://home.san.rr.com/glehmann/V6-TensionerBreak.jpg
I've pulled two tensioners that had the same kind of break. My friend
also experienced 2 such failures. I don't believe it's just a matter
of using the right technique... I think it's just a bad design. Your
mileage may vary (mileage between valve jobs that is.) I'm never going
to put another in one of my Alfas.