Thanks John. The customer says that resource pools are not used. And when I exported the MPP to XML via MS Project, the resources look identical to the other resources that imported fine, except that they had large IDs. We've only ran into this once.
What's straing is that if I click on "Resources" on the task, I get a drop-down where "Resource Two" is appended by "(Enterprise)". However, enterprise resource pool is not used. This is a modified file gotten from a customer, and I know know how they created those resources. Any ideas?