I think what lyric is trying to say (since we have talked about it) is that the default key mappings do not work in every case. On my system I have a Hauppauge Win-TV PVR USB2 plugged in all the time (except when I travel) and that causes several keys not to work in their default settings. I had to remap the very same keys lyric is having trouble with but when I unplug the Hauppauge everything goes back to working again.
I think his system has a geforce 240 in it (not exactly sure) and Im wondering if the audio portion of the card (not even sure if the 240 has that but something along those lines maybe) might be causing the issue?