Formula field on Object not calculated in report

Question

I have a number of fields on the Case object that are part of a field that is totalled:

IF( 

NOT( 

AND( 

Interpreter_Pay__c == null, 
Nurse_Pay_Rate__c == null, 
Interpreter_Hours__c == null, 
Interpreter_Travel_Fee__c == null, 
Site_Fee__c == null, 
Administrative_Fee__c == null 
) 
), 

Interpreter_Pay__c * Interpreter_Hours__c 
+ Nurse_Pay_Rate__c * Interpreter_Hours__c 
+ Site_Fee__c 
+ Administrative_Fee__c 
+ Interpreter_Travel_Fee__c 

,null)

The field calculates properly on the case detail page but when generating a report shows - on all records . Is there some limitation to salesforce stopping me here or have I missed something?

edit: none of the fields in the formula are formulas themselves; each will be manually entered.

Answer 1

IF( AND( ISNULL(Interpreter_Pay__c), ISNULL(Nurse_Pay_Rate__c), ISNULL(Interpreter_Hours__c), ISNULL(Interpreter_Travel_Fee__c), ISNULL(Site_Fee__c), ISNULL(Administrative_Fee__c) ), NULL, Interpreter_Pay__c * Interpreter_Hours__c + Nurse_Pay_Rate__c * Interpreter_Hours__c + Site_Fee__c + Administrative_Fee__c + Interpreter_Travel_Fee__c )