[Plugin: MailChimp] character set

I downloaded and activated MailChimp (v. 1.2.13) in order to start a mailing list for a newsletter. After activation, I didn’t have time to do any set up that day. The next day, I had strange characters appearing on my website, especially where an apostrophe should be. Like my character set was off. Could this be caused by activating MailChimp? I deactivated MailChimp that day and after refreshing my browswers, the problem was fixed. Has anyone else had this type of problem when installing MailChimp? I’d really like to use MailChimp if I can get around this problem. Thanks.