I don't have any clue about how Google works internally, but you could try to add some URL rewriting magic to your web server so that "/mypage/1" becomes "/mypa

I don't have any clue about how Google works internally, but you could try to add some URL rewriting magic to your web server so that "/mypage/1" becomes "/mypage.php?id=1" internally. A change like that might be enough to make it not look like it's all one page (assuming the parameters are really the problem).