I'm trying to run the GooglePlayServices samples but on the Auth sample I get the following error when pressing the Greet Me button:

com.google.android.gms.auth.GoogleAuthException: GooglePlayServices not available due to error 9

and Signature not valid. Found XXXX

the error is on the call 
GoogleAuthUtil.getToken(mActivity, mEmail, mScope);

I didn't do anything else, just compile and run the sample.

I do have the Google Play Services installed on my device. 

Am I missing something?

Thanks