Binary package hint: notify-osd

I am using notify-osd 0.9.3-0ubuntu1 (with /usr/share/ notify_ osd folder renamed to notify-osd) on Ubuntu Jaunty x64.
Whenever I use the (correctly working) multimedia keys on my keyboard, a Microsoft Wireless Multimedia Keyboard 1.1, I do not get any notification at all.
Play, Pause, Next, and Previous are all affected.
Notifications are working correctly for everything else.

Use cases:
1. I press "play" button on keyboard - I expect a confirmation bubble to be displayed with "play" icon, eventually (for enabled media players) with a consequent non-critical notification bubble with the title, author and cover of the playing track
2. I press "next" or "previous" - I expect a confirmation bubble with "play next" or "play previous" icon, with the eventual playing track non-critical notification bubble
3. I press "pause" or "stop" - as said on the Notify OSD specification previously linked, I should expect a confirmation bubble (the icons are not present on the icons table)