You are right, %item has either the Pre or Post matching part. But only in one case does it print anything!

Entry      : Pre | Post
  { use Data::Dumper; print Dumper \%item;}

# is equivalent to

Entry : Pre 
Entry : Post
  { use Data::Dumper; print Dumper \%item; }

# is equivalent to

Entry : Post
  { use Data::Dumper; print Dumper \%item; }
Entry : Pre

# is NOT equivalent to

Entry : Pre 
  { use Data::Dumper; print Dumper \%item; }
Entry : Post
 { use Data::Dumper; print Dumper \%item; }
[download]

And the last example is what you want