İf you have changed any settings in the credit master so the system is no longer checking against the correct set of data.

Running (from transaction SE38) RVKRED07 and RVKRED77 are both useful as they will re-oragmnised and re-check your credit data and values and will re-assign any orders and deliveries ( in structures s067 and s077) that are currently not being checked correctly. There is also a program RVKRED88 which basically simulates RVKRED77 and 07 without actually  updating anything so you can see what value it calculates without updating
the values.

We can use these reports regularly in order to ensure that any functional or master data udpates in credit management are reflected in the sales, delivery and billing documents you have on your system.

One word of warning - they can take a while to run so its best to schedule them overnight.