You must be new. This was a hot topic when the game was released in mid-July. You could hit the archives for old posts on the topics.
From what I remember, some people blamed the slowdown on either wide screen or HD TVs (X-Box users, I think). Some changed from the default camera to another angle, can't recall which one, to reduce or eliminate the problem. Some blamed it on the type of disk drive in their X-Box.
I use a regular TV and play on X-Box and have never experienced this problem, fortunately.
Just don't get me started the difficulty passing and the excessive dropped balls.