Tie::IxHash doesn't even work in that situation. The problem is that when you use a hash reference altogether -- that is, $hash{x} = { ... } -- you are creating a hash reference in Perl, and that is not "caught" by Tie::IxHash. You can't achieve the desired goal the way File is set up. You'll need to change it, no matter what you do.
Jeff japhy Pinyan,
P.L., P.M., P.O.D, X.S.:
Perl,
regex,
and perlhacker How can we ever be the sold short or the cheated, we who for every service have long ago been overpaid? ~~ Meister Eckhart