I don't know about if that upgrade is safe or not (somebody else will tell you) but I recommend backuping your c/cygwin64 directory so that you can go back if anything goes wrong :)
LLoyd -- Problem reports: http://cygwin.com/problems.html FAQ: http://cygwin.com/faq/ Documentation: http://cygwin.com/docs.html Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple