Research in Motion is in court again. This time RIM has filed suit to <A HREF="http://news.com.com/2100-1041_3-5057532.html?tag=lh">prevent Xerox from demanding patent royalties</A>, according to court documents. RIM, which is already in patent litigation with NTP and Good Technology, said it filed its suit against Xerox on July 17 in a federal court in Hartford, Conn., as a defensive move. News.com reports that Xerox claims that RIM has infringed on some of its patents, and RIM said Xerox has been threatening a lawsuit since August 2002.