[Jman423]

As mentioned earlier, this MOD forces the Private Message system to use whatever template is defined in the settings (of the MOD).

There has to be a way to exclude the PM system from using this postbit style.

EDIT: I just got this issue resolved for myself

Just change the plugin "First Post's Template" to the following code, and it will not affect the PM system.

if (THIS_SCRIPT != 'private') {
global $vbulletin;	
if($vbulletin->options['fpoap_active']){
	if(!in_array($this->thread['forumid'], explode(',', $vbulletin->options['fpoap_excluded_forums']))){
		if($this->thread['firstpostid'] == $this->post['postid']){
			$this->templatename = $vbulletin->options['fpoap_template'];
		}
	}
    }
}

Please keep in mind, I am not a coder, I just messed around until it worked. This may not be the best way to achieve the desired outcome.