And I still say Belfour was average against Ottawa and below average against Philadelphia. I don't know if you saw the games (you sure did find the game statistics alright), but if you imagine someone lying unconscious in goal wearing goalie equipment, and then imagine Hossa firing 44 pucks in his head, then the unconscious person would be awarded with 44 saves in the post game statistics. That's almost how it was (slight exaggeration ). But he was slightly better against Ottawa.
Against Philadelphia he made some great saves, a lot of ordinary saves (when people just shoot the puck at you) and had a bunch of fumbled shots, even from the mid zone. A team that trusts its goalie know they can make a mistake every once in a while and expect the goalie to bail them out. When they have that trust, they can play their own game and concentrate on creating offence (or whatever their game plan is). If, on the other hand, the goalie is unreliable, the team will not be able to play their ordinary game because everyone's afraid to make that mistake that will cost them a goal. The first thing they lose is their offence and even then their defence isn't getting any better (as offence for an offensive player is his best defence) and most often they end up losing the game.
By the way, save percentage is also misleading (especially in the Ottawa series) since getting a shutout skews the numbers (Belfour got two).