Probably an auto-correct mistake. I don't mind my text editors underlining words it thinks are spelled wrong, but as anyone with an iPhone knows, auto-correcting text can be bothersome. I don't have one myself, but the website www.d*a*m*nyouautocorrect.com is really funny. Be forewarned, it's not always rated PG, btw.

(remove asterisks for proper URL)

Brian