Weird Beeping Sound...

[andyli]

When I type "YU" and for some reason, I don't fully release the "Y" before pressing "U" my computer makes a strange beep, kinda letting me know that I am pressing two keys at once... but this doesn't happen if I use another key combination. (Must be holding shift... for example, I was NYU).

Am I hitting some kind of shortcut key? Or is there something wrong with my unit?