Debug Wordpress Plugin - Posting to Twitter

My wordpress plugin automatically posts old wordpress posts to Twitter. It takes the number of posts you select and posts them based on an interval selected. The problem is that every hour, when the plugin is supposed to post, it keeps posting on Twitter many, many times instead of the number of times specified in the plugin. For example: Number of Tweets: 1 Interval (hours): 1 This should post 1 tweet every hour to Twitter. However, the plugin keeps posting over and over again as if it had never posted. It ends up spamming on Twitter until the tokens to post run out. I need this fixed so that the plugin does not post again until it's supposed to post again and when it posts, it will only post the number of times listed in the plugin. Attached is the plugin files for you to review and test.