I have installed your Latest Tweets plugin on 2 WordPress sites, including a site that I just use for testing. Both of them produce this 'Serialised Data' (I'm only assuming that's what it's called, because two previous posters refer to it thus).
The problem is not consistent. The first time I display the page, it (usually) looks fine (but includes an odd 👍 'square' character). Further refreshes of the page (or visits from a different browser/machine) exhibit this problem.
The problem is on both WordPress installations (both on 3.7.1).
The problem appears to be related to a tweet which:
- Was created on an iPhone;
- The iPhone has the 'EMOJI' app installed;
- The 'EMOJI' keyboard was selected; and
- The user typed a 'thumbs-up' symbol as part of the tweet.
I hope that this information helps you to troubleshoot the problem.