I don't know why your comment is downvoted -- this is acutally a legitimate issue mentioned in their terms of service.

StartSSL generally don't mention their terms, so a lot of the use of 'StartSSL Free' is commercial. People don't like to hear they've been misled (and shoot the messenger).

They actually started policing this and refuse to renew a certificate if they decide it's a commercial use. Happened to me and rather than argue with them (it wasn't), I bought a $5 one at ssls.com...