ADB doesn't recognize my Galaxy Nexus

I just bought a Galaxy Nexus, now I got a problem, my ADB doesn't recognize it. The Point is when I connect it, it shows it as Storage-Device on my Computer but it isn't listed as an ADB Device.

When I connect my other Phone (HTC Desire HD) it recognize it without any problems.

Some information about the System and Config:

I'm on Win7 Service Pack 1 64bit
Galaxy Nexus is in debugging mode
The Device isn't shown in ADB but Windows recognize it as Massstoragedevice
Eclipse and Googlepack is updated to the newest Version

Why my device is not showing in ADB devices?

On Android 5.0, go to Settings -> Storage -> menu -> USB computer connection and make sure 'Media device (MTP)' is disabled. When it's disabled 'adb devices' lists the device, when enabled not.

Check if you have installed this package in your ADB "Google USB Driver package, revision 4"; if not do it.

Another possible solution could be downloading the drivers from here: http://www.samsung.com/us/support/owners/product/SCH-I515MSAVZW

This appears to work for the Samsung GT-i9250 version too.