I received a large order 3 days ago. I pulled all of the issues, reviewed each issue and made some grading adjustments.  The buyer was notified by email  twice, but the order was not reviewed and approved yet.  I have had no response from the buyer.  His own store site on Atomic Avenue states that he is on vacation.  I can't ship the order until it is approved. What should I do in this situation?

If you haven’t already done so, definitely email AA support. You’ll get a faster response there than from the msg boards. (Plus, the response will be more specific re: your transaction since AA support can see all of your details plus your buyer’s details. 

Thanks.