AP and Expense Report SLA rule not working in AP

We have a requirement to derive Project based expense report as well as Project based Ap invoices with POET details so that

If task is CAPITAL - then Cost Center is ****   (irrespective of AP or expense or any source )  

If task is Expense then Default CC (from DEA)   - only for Expense reports

and When task is Expense for any Other source than Expense: Cost Center should be @@@  

The SLA rule created is as below :

1. Account Rule : assigned Project Rule ( the project rule is for 'Task Capitalizable Indicator' = Y : CC=***) and for  'Task Capitalizable Indicator'= N,  CC=@@@)   with condition as Source not equal to Expense Report ( "Invoice Source"(AP,S,S) != EMP_EXPENSE_REPORT)