I have fully updated ubuntu 12.04 installed on my desktop. The problem is when I turn on NumLock, the keyboard behaves like a laptop keyboard making the keys "mjkluio789" correspond to "0-9". I've had a laptop where such behavior was expected due to absence of a separate numpad. I'm using an iBall USB keyboard and it has a numpad section unlike laptop keyboards(http://iball.co.in/Product.aspx?c=2).