'mktorrent' is not creating private torrents

[GKNByNW]

I upload to various private trackers every now and then. Rather than using my seedbox or local client to create the .torrent files, I switched to the mktorrent command so that I can automate my .torrent creation through a simple script. Here is a sample of the command syntax I am using:

mktorrent -a {ANNOUNCE URL} -l 20 -o {OUTPUT PATH & TORRENTNAME} -p -v {SOURCE FOLDER}

Obviously I substitute the appropriate announce based on what site the .torrent is for, as well as change the piece size to the appropriate number (in this case 2^20, or 1MB piece size) depending on my requirements. As far as I can tell I have the correct command syntax (I don't get any errors from it, at least) but only certain .torrents actually have the private/no DHT flag set when I check them after creation. Unless I am overlooking something, this is occuring on the sites that use a PHP announce. For example, when I use the following trackers:

https://ssl.torrentsite1.com/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/announce

and

http://tracker.torrentsite2.com:2710/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx/announce

the .torrent files show up as private. However, announce URLs like this:

http://torrentsite3.org/announce.php

do NOT show up as private, though it seems DHT IS disabled.

Sooooo...... does anyone know if this is a bug in mktorrent, or am I doing something incorrectly? Google was of no use to me on this one