QRCVDTAQ vs Varying length fields

...
 /Define qrcvdtaq 
 * Receive data from a data queue. 
D qrcvdtaq        PR                  EXTPGM('QRCVDTAQ') 
D  DataQue                      10A   CONST 
D  DataQueLib                   10A   CONST 
D  DataLen                       5P 0 
D  DataRead                  32702A   OPTIONS(*VARSIZE) VARYING
...
D DataLen         S              5P 0
D DataRead        S            250A   VARYING
...
C                   callp     qrcvdtaq('EXCLEIACT':'*LIBL':DataLen:
C                                      DataRead:-1: 
C                                      ' ':0:'':0:'':'*YES':200: 
C                                      ERRC0100P 
C                                     ) 
...

According to the compile listing, the next line is 1310
C                   if        %subst(DataRead:1:DataLen)<>'*SHUTDOWN'
...
RNX0115 - 
Message . . . . :   Length of varying length variable is out of range.  
Cause . . . . . :   The length of a varying length character or DBCS 
variable
  is less than 0 or greater than its declared maximum length in RPG 
procedure
  EXCLEIACT in program GDIHQ/EXCLEIACT.  
Recovery  . . . :   Contact the person responsible for program maintenance 
to
  determine the cause of the problem.  
>From program . . . . . . . . . :   QRNXIE 
  From library . . . . . . . . :     QSYS 
  From module  . . . . . . . . :     QRNXMSG 
  From procedure . . . . . . . :     SignalException
  From statement . . . . . . . :     21 
 
To program . . . . . . . . . . :   EXCLEIACT 
  To library . . . . . . . . . :     GDIHQ 
  To module  . . . . . . . . . :     EXCLEIACT 
  To procedure . . . . . . . . :     EXCLEIACT 
  To statement . . . . . . . . :     1310 

Once again, dump terminated.

Rob Berendt
-- 
"They that can give up essential liberty to obtain a little temporary 
safety deserve neither liberty nor safety." 
Benjamin Franklin