Hey Mike,
Have the mappings changed at all, some types of mappings take a considerable amount longer than others? Is the overall file size the same between the two loads? Also is the 5 minutes in your production environment and the 40 min in the QA? Are the two environments specd out the same from a hardware standpoint? It isn't uncommon to have a QA/DEV scaled down from a hardware perspective. One more item I would look at is the logs of the load itself to see what step is taking the longest. You can click on the three bars in the far left to see more detail of the task in task activity to help to point you in the right direction.
