Unfortunately, the "e" and "Power" top two keys are dead and can not be used in Raspbmc - not even by the configuration file keyboard.xml. If you want so can shut down the Raspi with the FB, you have to the shutdown action put on any other button, eg 'Close' (bottom left).
Inexplicably, in XBMC have the volume buttons ("Volume") no repeat, the opposite channel selection keys ("Channel") to page through lists uselessly but already. By making changes in the file keyboard.xml I have therefore the function of the volume and channel buttons interchanged (instructions can be found here: [...]
Edit: Unfortunately, the above link has been censored to my thread in the "Raspberry Pi Forum". So just google itself to "Keys / Remote Control Functions Hama MCE Remote Control" (post # 2).