relay-bin file missing

I am missing my *-relay-bin file on my slave so I got an error on my show slave status; . The slave is stopped, now I want to resync but whenever I do a change master_log_pos and master_log_file it outputs a ERROR 1105 (HY000): Failed purging old relay logs: Failed during log reset what should I

Upgrade glitches

Hi, I am about to upgrade from mysql-standard-4.0.14 to mysql-standard-4.1.7 on two Red Hat ES 3 server (master/slave circular relationship). I would like to know about any glitches I might face while doing so... Has anyone had any problems or bugs with any incompatible directives. Here is the