Wireless keyboard installation (pairing) not working

Hi,

I just bought a wireless apple keyboard. I now want to pair it with my MacBook Pro. If I turn the keyboard on, no wizard window appears at first. The green light on the keyboard blinks. If I start the installation wizard manually (from the Bluetooth pane in the System prefs) the MacBook Pro recognizes the keyboard. I click on Next and I see a big bold number and a text which says I have to enter this number to pair the keyboard. But there is nothing where I can enter this number. After 20 seconds I see a red message telling me that the keyboard could not be connected and that I have to verify if it's in distance and turned on???

My OS is up-to-date, the batteries are new, the keyboard is in distance and turned on. What now?

Funny thing is that it works perfectly on the VISTA partition :S

Help