Apparent bug-fix in RPG compiler breaks program

So I'm trying to wrap my brain around the following...

DS defined like so:
DlvData DS
D lvFeeCD 30A
D $FEE01 3A Overlay(lvFeeCd:1)
D $FEE02 3A Overlay(lvFeeCd:*Next)
D $FEE03 3A Overlay(lvFeeCd:*Next)
D $FEE04 3A Overlay(lvFeeCd:*Next)
D $FEE05 3A Overlay(lvFeeCd:*Next)
D $FEE06 3A Overlay(lvFeeCd:*Next)
D $FEE07 3A Overlay(lvFeeCd:*Next)
D $FEE08 3A Overlay(lvFeeCd:*Next)
D $FEE09 3A Overlay(lvFeeCd:*Next)
D $FEE10 3A Overlay(lvFeeCd:*Next)
D
D lvFeeTyp 100A
D $AMTTYP01 10A Overlay(lvFeeTyp:1)
D $AMTTYP02 10A Overlay(lvFeeTyp:*Next)
D $AMTTYP03 10A Overlay(lvFeeTyp:*Next)
D $AMTTYP04 10A Overlay(lvFeeTyp:*Next)
D $AMTTYP05 10A Overlay(lvFeeTyp:*Next)
D $AMTTYP06 10A Overlay(lvFeeTyp:*Next)
D $AMTTYP07 10A Overlay(lvFeeTyp:*Next)
D $AMTTYP08 10A Overlay(lvFeeTyp:*Next)
D $AMTTYP09 10A Overlay(lvFeeTyp:*Next)
D $AMTTYP10 10A Overlay(lvFeeTyp:*Next)
D
D lvFees 3A Dim(10) Overlay(lvFeeCd)
D lvFeeTypes 10A Dim(10) Overlay(lvFeeTyp)

but in the calculations, the code has...
lvData.lvFees(lvCnt) <snip>

Compiling on a v7r2 box, with TGTRLS(*CURRENT), the compile fails
with RNF7591: An operand of a qualified name expression is not valid.

But with TGTRLS(V6R1M0) which is what we used to use, the compile completes
successfully.

We added the QUALIFIED keyword to the DS, and the compile succeeds. But
the program doesn't work correctly.

One of my team mates is working on debugging what is going on, but I
thought I'd see if I could understand what was actually occurring with the
working program, w/o QUALIFIED, when TGTRLS(V6R1M0) was used.

Anybody seen this?

Thanks!
Charles