Terrible time with this repeated error!

Hi all,
The following error is repeating and creating terrible
time , I have tried all possible solutions but they
are nt working , Can some one help me out with better
solutions.Thank you somuch
======================================================
 Job:   YEQC1 

Not able to allocate objects needed for file YPOSF1 in
library QS36F     
member or program device YPOSF1.Error message CPF4128
appeared during
 OPEN for file YPOSF1.           

Function check. RNX1216 unmonitored by YEQR1 at
statement 0001000001,
 instruction X'0000'.Error message CPF4128 appeared
during OPEN for file YPOSF1 (C S D F).    
Checked for object locks and found the following 

Opt  Member      Job         User        Type    Lock 
   Status  Share

     GMIPOSF1    RBT_GDBPOS  D_MIRROR    MBR    
*SHRRD    HELD

                                         DATA   
*SHRRD    HELD     

I could not find out any job locking this file other
than one listed above.

RBT_GDBPOS runs for almost one hour , everytime i have
to wait till it completes
 and then take Cancel and Retry...

i cant kill this job since it is very important one ,
its reading YPOSF1 and loading the Global Database..

I have tried following solutions :

1)  I have changed S36 options 
Shared opens of files . . . . . . . . .   Y 
Store deleted files in cache  . . . . .   Y 
to 'N' , however it didnt work and errored out in same
error ...
2)I can not implement strictly  ALCOBJ 
command just before calling this program YEQC1 and 
then execute DLCOBJ as soon as
this program ends because it is going to abend
RBT_GDBPOS job....

3)Before calling the rpg program YEQR1 I have included
following code in my cl
 program YEQC1 but it didnt work out and it resulted
in  same error.

OVRDBF     FILE(YPOSF1) TOFILE(&SLIB/YPOSF1) +    
             SHARE(*YES)                              
CALL       PGM(YEQR1) 


=================================
Can some one advise any better solutions how to handle
this error in production 
from reoccuring, would appreciate your help
Thanks in adv,
Murali.                                              


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