Links in Admin/statistics not active

Hi guys, I am trying to add customer group discounts but when I go to Admin/Customers the link is not active, infact the only link that is active is "reviews pending approval" and all the links in the "orders" area are active. All other links are inactive. My biggest problem is that I need to get into the orders total module (in the customers link) to add another group discount but I do not know how to get in there, is there another way or must the link be working? The link may have become inactive after installing an add-on, maybe the profit margin calculator...but not sure exactly. Any ideas on how to fix this? Is there a place to edit the php to get the links working again?

Cheers,

Jeff Cunningham
Cracked Kettle Amsterdam