Project Accounting Error Message in Purchasing

I am having difficulty in getting the project accounting to work on a Project PO. I have setup 5 new Project Organizations (one each for each new operating unit). Four of the operating units have their own ledger. For two of the operating units, one that shares a ledger and one that has it's own ledger I get the following message. Error: Process Default_Charge_Acc_Generator not completed. When I click on details I get the error msg APP-PO-1040: Please enter a valid charge account. Cause: Charge account is mandatory and you did not enter one. Action: Enter a Charge Account.