I'm a little late coming in on this one... but oh well. Blocking the trem is one way to go about it... and if you already have done so... then that should work. But I would have suggested screwing the trem claws in so that they pull the bridge tight to the body of the guitar. This does basically the same thing... except you still have some use of your trem if you really want to use it. Adjusting the bridge angle may throw the intonation off slightly depending on how high it was set before the change...

The G string buzz can also be caused due to a lack of tension on the string at the string tree... Sometimes string trees get pulled out slightly as a guitar ages...and the result is a lack of tension on the nut. This lack of tension causes a string to rattle or buzz really bad in the nut. Check your string retainers to see if they're tightened down... if not tighten them down.