I do not get the option for Need or Greed rolls

This has happened to me every time I have been in a group so far. An item will drop that you can only get by picking need or greed when it comes time to roll on the item that drops but for some reason the need or greed roll option has not popped up for me to click. It has for the people I have been in group with though and this is not a huge problem right now because im only lvl 43 but once i start in higher end instances and what not it will be a problem if I can not even have a chance to pick need or greed to try and get an item. Please help with any information on how I might go about fixing this problem. Thank You.