Sites brought down – plugin needs fixing ASAP

I had a thread going here (http://wordpress.org/support/topic/tweets-arent-being-sent), but it was marked as closed well before the problem was resolved.
Anyway, the two sites I had this installed on both starting running at a snails pace and eventually both sites went down – 500 internal server error on one, and the other was restricted by my host because it was causing high loading issues on the server. All other sites on the same server were OK.
I’m disabling this plugin for the foreseeable future until a fix is in place.

https://wordpress.org/plugins/tweet-old-post/