Bluetooth Keyboard (2 battery) - Battery Life not updating

Hi

I have a 21" 2009 iMac. I have noticed that despite having all the latest updates (OSX and firmware), the percentage battery life does not change for my keyboard (when you hover over the "Apple Wireless Keyboard" in the bluetooth menu). If I turn the keyboard off then on, it does update to give me the latest battery life.

Also noticed the wireless keyboard does not show up on the iStat Nano widget like it says it should.

Any suggestions?

Paul