Big Business 13.36 adds a setting to Unblock Repricing. This lets you override new behavior that blocks repricing automatically.
The problem is with Qty Pricing or As Quoted Pricing you can give a customer a bulk price ($5/ea for 100) and have it automatically replace the default price ($6.95/ea). So, they order 100. If you invoice 50, though, Big Business could revert the price.
Now it does not revert the price, but still can if you choose Unblock Repricing.