Curly brackets create a hash, initializes it with the contents of the curlies, and returns a reference to the hash. So

my @addr = {$one, $two};
[download]

means

my %anon_hash;
$anon_hash{$one} = $two;
my @addr = \%anon_hash;
[download]

Obviously, that's not what you want. To build a list, use parentheses.

my @addr = ($one, $two);
[download]