I've been able to get it to work without the Improved Validation Link plugin, but I mainly only use IVL. I'm going to send in a ticket with my information so you can check it out 
Also - I found this code in twitter_auto_tweet.php
Code:
curl_close($ch);
if($resultArray['http_code'] == "200"){
$twitter_status='Your message has been sended!';
} else {
$twitter_status="Error posting to Twitter. Retry";
}
return $twitter_status; Where should I see the twitter_status being displayed. Even when I got it to work without IVL, I never saw that the plugin ran successfully or not.