I am using merlyn's/perlmonkey's solution on how to match comments and quotes. When I do the following:

%hash = ('"', '"', '/*', '*/', '<-', '->');

foreach (keys(%hash))
{
$start = $_;
 $end   = $hash{$_};

   my $inside = 0;
   my $oldpos = 0;

  while ($string =~ /(?<!\\)(\Q$start\E|\Q$end\E)/g) {
      if ($inside == 0) {
   $oldpos = pos($string) - length($start);
  $inside++;
 } else {
 push (@a, substr($string, $oldpos, pos($string)-$oldpos));

$inside--;
}
                  }
}
[download]

the code works and @a gets all the matches.
But when I create my %hash differently, like:

while($db->FetchRow())
  {
   undef %mult;
   %mult = $db->DataHash();
   push (@multy, values(%mult));
  }
%hash = reverse(@multy);
[download]

and then run the same code as above, my $string gets split by character, and each element of @a receives a single character.
What's the difference and how do I fix that?