Apps Exception in google map application...

[android_beginner]

hi..
i m new to android..
i m trying a basic application of google map..
i have registered and got the api key..
bt when i m trying to run the application, i m getting the exception :
(this is the log)

E/AndroidRuntime( 753):
java.lang.RuntimeException: Unable to start activity
ComponentInfo {com.android/com.android.activity}: java.lang.UnsupportedOperationException:
Can't convert to dimension: type=0x12

can anyone help me?
thanx in advance..