Thinking about upgrading mySQL to version 5.2.10 and and PHP to version 5.0. Can aMember 3.1.8PRO handle these versions, didnt find anyone else on the site asking the same question, but I am sure its come up before.
Only issue I've heard of for newer versions is PHP 5.3: http://www.amember.com/forum/showthread.php?t=10470