I was just looking for a place to highlight this as one of the most irritating issues of FM 2011.
First of all, if you take most leagues, you will have most goalkeepers amongst the top 30 best players in the league, because they usually get higher ratings IRL. Secondly, any goalie that does not concede and makes three crucial saves will most likely end up as the man of match.
I think goalie behavior is ok in the game, they are not saving too many shots are letting too many through, it's just that the rating system is poorly implemented. Of all the things that could do with some tweaking, I would imagine goalie ratings shouldn't be that hard, as there is a pretty consistent correlation between shots on target and saves which is really not reflected in the rating the goalie gets after the match.