Cannot make interception on madden football game

I have been playing the new nfl madden game for playstation3 but is it just me who is struggling to be able to even make any interception at all.. every time I press triangle all of my players just seem to do the same and knock the ball to the ground instead of actually catching it it is rather annoying to say the least. Even for the most easiest catches in the world and what ever team I play even the very best non of my defenders can even make a catch at all. Does any one have any tips for me so I can make a successful interception? or is it all down to luck and I am really unlucky when it comes to this game? Thanks!