I opened a drop down menu (File) and opened a sub-menu (Recent); found the name of a file, then went looking for it using a gui file browser
(oh yeah LO v4.1.3.2, Ubuntu 13.10), and the LO drop down menus "stayed on top" and blocked my seeing the browser file, even though it had the 'focus'.
Is this a boo-boo, an anomaly, or a feature,
John