Good point ++dws. I tried stepping by 1 (since 130171 is prime :-/) and it worked. I came back after doing a little work solving a stupid math error on my part with this code:

...
    my $readamount = int(($length - $got_so_far)/8192)?8192:$length-$g
+ot_so_far;
    while ( ($got_so_far < $length) and read( $sock, $buffer, $readamo
+unt ) ){
        print $fh $buffer; 
        $got_so_far += length $buffer;
        $readamount = int(($length - $got_so_far)/8192)?8192:$length-$
+got_so_far;
        print "Got: $got_so_far\n" if $DEBUG;
    }
...
[download]

and you had already made the points I was going to make. However, to the OP: Hope this helps.

Update: Thanks to dws for pointing out a possible block situation. Note to the OP that the read under init_download should probably choose a smaller chunk to be read. Of course, you could also just use sysread. :)

antirice    
The first rule of Perl club is - use Perl
The ith rule of Perl club is - follow rule i - 1 for i > 1