Wireless Keyboard/Magic Mouse not recognized in Mac OS X

Hi everyone,

I've recently bought a new iMac which I Boot Camped yesterday, just like I'd done with my old iMac. With my old iMac I had to use a USB-keyboard and -mouse because the wireless keyboard and Magic Mouse weren't recognized. With this iMac, however, I've encountered a problem to which I can't find a solution anywhere on the internet.

I run Mac OS X Lion and I've installed Windows 7 via Boot Camp. After updating the Boot Camp-assistand in Windows and installing the drivers my Windows environment works perfectly - even the scroll feature of the Magic Mouse works without hassle.

The problem: when I boot back into Mac OS X Lion, my wireless keyboard and Magic Mouse aren't recognized as such... which means I now can't use the volume up & down buttons, the mission control and dashboard buttons, and my mouse has been reduced to a two button mouse with which I can't scroll pages anymore. As a matter of fact; pages now have visible scroll bars which I have to drag up and down to navigate through the page.

This is extremely annoying - especially since I can't find a solution or even a similar thread anywhere! Is there anyone who has experienced this also? As you can understand I want to solve this problem before I uninstall Windows.

Thanks in advance!