Multimedia keyboard input

Reaper doesn't receive extra key inputs (play, stop, next track etc.) from multimedia keyboards, when the main window doesn't have the input focus. So, when floating windows (e.g. plugins) are in foreground, pressing the key "play/pause" for example doesn't work, although the action is defined.

The last time, when I tried Reaper (a version 3), it was possible. Multimedia keys are very important for DAWs (transport functions), because usually they are independent from the input focus.