I'm experiencing a lot of popup focus issues on 10.5.
That one that is most annoying is that it an active "Show Usages" (Ctrl-Alt-F7) popup will not consume keyboard events.
This usually causes me to navigate within the underlying editor, and insert unintended line breaks.
I see that Peter has already reported this one: http://youtrack.jetbrains.net/issue/IDEA-66735
Depending on who's reading this, add your votes or fix it ;)