Pointer / Based issue

I have a program that contains a data structure and a pointer defined
as:
 
d FeatTypeDS                ds             Qualified
d   dsFeat                                3     dim(1000)
d   dsType                               2     dim(1000)
 
d    PointerToDS             s          *
 
I set the pointer by using:
PointerToDS = %ADDR( FeatTypeDS )
 
I have a procedure called ErrorsInDS in a service program that accepts a
pointer as a parameter and returns a Boolean. I get to the procedure by
using...
 
If ErrorsInDS( PointerToDS );
 
In the service program I have the procedure interface defined as
p  ErrorsInDS                 pi                   n
       PointerPassedIn                            *
 
I also have a data structure in the procedure defined as
d FeatTypeDS                ds             Qualified
Based(PointerPassedIn)
d   dsFeat                                3     dim(1000)
d   dsType                               2     dim(1000)
I'm trying to manipulate the data within the DS from my service program
without duplicating the contents of the data structure and without
actually passing the data. I figured the DS in the service program would
be exactly as the DS in the calling program but it's not. The memory
address leaving the program, PointerToDS, and entering the service
program, PointerPassedIn, is exactly the same but the contents of the DS
in the service program is not the same as the DS in the program. The
program has valid data. The DS is the service program contains all
asterisks. 
 
Any ideas what I'm doing wrong?
 
 
Thanks,
S. Ellsberry