Sql Help Needed.

Below is a sql that works... But does not work the way I feel it should... But since I'm very new to the sql syntax, I must be missing something...

Problem..

Table A  (indexed by date) is linked to Table B, via a Transaction #.
Table B (Indexed by Transaction #) but linked to Table C, by  Item#, Size Code, and a Requistion #.
Table C (Indexed by Item#, Size Code, Req#)

The problem is this... For some reason, it's not using the index for table C, its creating a copy of C, and creating an access path...

I was hoping some one could take a few moments from their busy day, and offer a few helpful suggestions to get me going...

SQL Code is as follows...

select *                                                                 
from (prdjrnusg A join jpldcusgsm B on A.pjstr# = B.jpstr#)                                                
  inner join pmlrd6 C on (C.rdicde = B.rdicde) and                       
                        (C.rdsize = B.rdsize) and                        
                        (C.rdrid  = B.rdrid)                             
                                                         
Thanks, tim...