Having poor table declarations flagged.

Hi during our test phase for COBOL 6 we encounter an memory overwrite after recompiling a program. The abend is linked with the new STGOPT
option wich had discarded some unused items after the chart

Here's the failing syntax this chart is defined in working storage
section and is in the last items:

01 LL-MEGB PIC S9(4) COMP.
01 COMMAREA-MEGB000T.
05 MEGB-OU-ALLER PIC X(08).
05 MEGB-QUESTION.
10 MEGB-FICH-MAJ PIC X(08).
10 MEGB-CDRET PIC X(02).
88 APPEL-OK VALUE 'OK'.
10 FILLER PIC X(01) OCCURS 1 DEPENDING ON LL-MEGB.
For me the declaration is unconsistent. In fact it was working simply because behind the last chart level there was unused data items, now removed by data item.
1/ There's no precision on the max size of the chart.
2/ The depnding on clause suggests that the max size could be let's say
9999 (With TRUNC(OPT)).

Why the compiler don't flag the lack for the second parameter wich is
the max size of the chart ?