I am using version 3.23 with no problems whatsoever you might want to check to make sure that all your tables are myisam tables and post your my.ini (cnf) file contents so that others can take a look. also the database size and the aproximate number of users that are on at any given time might help to diagnose your problem.
My point is that upgrading the database software may do absolutely nothing for you. Upgrading is not always the best way to fix a problem.
