Menus unrensponsive after 13.10 upgrade

After a 13.10 upgrade which seems otherwise allright, I am experiencing some delay and unresponsiveness when clicking on menus in the global bar. This happens on two computers of mine, both upgraded to 13.10. I am wondering if, before going through a clean install, there is something I can try (like trashing some preference or uninstalling some package). I know it's nearly impossible for anybody to know what my issue is - must be something I installed on both pcs, but what? - but maybe you can point me in the right direction. Thanks!