Better monks than I,

So, I've got this input file name in $ARGV[0], and then three-tuples follow that, composed of an output file, and two csv lists of numbers (I call them maps) :

/bin/perl test.pl input out1 0,2,4,6 0,1,2,3 out2 1,3,5,7 0,1,2,3
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Okay, so here is a test loop to populate an array of hashes, each hash containing some useful stuff about each three-tuple.

for ($ii=1;$ii<=@ARGV-1;$ii+=3)  # three-tuples (outfile, map1, map2)
{
  $files[(($ii-1)/3)]{fname}=$ARGV[$ii];
  $files[(($ii-1)/3)]{fhandle}= new IO::File ">".$files[(($ii-1)/3)]{f
+name};
  $files[(($ii-1)/3)]{map1}=[split /,/,$ARGV[$ii+1]];
  print "map1 : [" . join /,/,$files[(($ii-1)/3)]{map1} . "]\n";
  print Dumper(@files);
}
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Well, the wierd thing is that the second to last print statement prints something like:

map1 : [ARRAY(0x1dc518c)]
$VAR1 = {
          'fname' => 'out1',
          'map1' => [
                     '0',
                     '2',
                     '4',
                     '6'
                   ],
          'fhandle' => bless( \*Symbol::GEN0, 'IO::File' ),
        };
.
.
.
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... instead of:

map : [0,2,4,6]
.
.
.
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I've tried adding various brackets and parens (admittedly, not the best way to debug) to try to ensure proper context, but to no avail.
Yes, I know that I could simply print $ARGV[$ii+1] but that really wasn't the point. Ignoring stylistic and readability concerns (those will be woven into working code, not this cruft) what's wrong with the code?