Unfortunately there’s not really much we can do there. We’re simply using WordPress’s built-in Simple Pie system to pull from Twitter’s RSS feed. The theme takes your twitter username, puts it into a URL For Twitter’s RSS, and uses WordPress’s
fetch_feed to pull the data. — http://codex.wordpress.org/Function_Reference/fetch_feed
The way it works is it pulls the data every two hours and caches it (our theme filters this from WP default 12 hours to 2 hours). That message is the theme’s way of relaying to yo that Simple Pie sent back a WP Error. I have found that when you’re getting inconsistant results with this, it’s generally an issue of your server timing out on retrieving the data. I don’t know what your setup is, but If you’re any kind of inexpensive shared hosting plan, or have limited resources that vary, it’s possible that the issue is simply that sometimes you’re able to pull the data and sometimes it times out.