[otrs] "This message was written in a character set other than your own" error message

I'm getting this error message on an incoming email that OTRS checks: "This message was written in a character set other than your own. If it is not displayed correctly, click here to open it in a new window." The email is from a web form generated by tfmail. I have confirmed that both character sets (tfmail and otrs) are iso-8859-1. What gives? Thanks, Carl Sheline csheline@llu.edu