Question on Open Credit Authorization

I am having a question on Customer Credit Limit.
Available credit limit = Credit Limit of the Customer (set at account profile level) - total balance - sum of the open credit authorizations
Customer credit limit is 18000000
Total balance in AR is 1600000
sum of the open credit authorizations 4000000
Total = 20000000
As the sum of total balance in AR + total REM_AUTH_AMOUNT is exceeding the credit limit, all the new orders are going on hold. Now the question is
When I query the sales orders against the REM_AUTH_AMOUNT, the orders are in closed status, how ever the revision orders are on Awaiting shipping. I am able to query these orders only with Open status equals null.