Problems Using a DOCTYPE in APEX Theme Templates
But… Sara pointed out to me that APEX 3.2 was about to be released and had already been installed at apex.oracle.com. Deciding I had nothing to lose by testing it out I uploaded my application and theme, with DOCTYPE, and lo and behold, the menus all work! It would seem the offending functions have been updated to rectify this problem which means I can go on developing shiny new standards compliant APEX themes. So, a big thank you to whoever was responsible for the update; you’ve saved me from a massive headache!