how to show function calls from tkprof on Oracle 11G?

Hi,

I have a procedure p1 which in turn call other functions in a query.  I like to get info about the function calls and the execution plans, cup time. elaspsed time etc for the queries inside the function. But when I run tkprof on the procedure p1, I don't see theese function calls from tkprof trace files. It worked on 10G but not working on 11G

My database is 11.2.0.2 on Linux

The code is something llike this:

PRODCEDURE p1

IS

BEGIN

select  cust_name, fi(cust_id) as total_purchaes

from customer;

END;/

Where f1 is a function like