How is the Credit Limit field in the P42050 calculated?

We have updated the credit limit on a customer to 1,500,000 and the Credit is checked based on the customer number (C).  We have sales orders going on hold because the system calculates the credit limit at 1,202,983 dollars.  For a test we changed the credit limit on the customer master to 1,000,000 and the credit limit field on the P42050 changed to 800,000.  We cannot find any settings that would set the credit limit to be 80% of what we entered.

Thanks