Hello, A little emberassed here because I am stuck on a "fundamentals" issue and I can't seem to figure out what I am missing. I have created 2 custom objects and a master-detail relationship between the two of them. I have put the field "Units__c" on object "Child__c" and would like to put a rollup summary titled "Total_Units__c" on "Parent__c".When I go to create my rollup summary, the "Field to Aggregate" dropdown becomes grayed out and I can't select "Units__c" from the list. "Units__c" is a number field. I can't seem to figure out why I can't do this, and its driving me nuts!! Have a reached a limit on Rollup Summaries for my org? I am using EE and only have a handful of them. I am sure that I am missing something pain-stakingly obvious, can anyone help?Thanks, John