Calculating tax when a Country is selected

Summary

Expense location is setup as 'Country and State or Province' - calculating tax on Country

Content

In 'Manage Expenses System Options' we have our 'Enable Expense Location Level' set up as 'Country and State or Province' 

We also have the 'Pay Expense Reports Through' set as 'Third Party' - our third party is PeopleSoft Financials v9.2

We are a Canadian college.  Our processing and voucher processing is working successfully until we enter an expense location of 'Canada', the voucher build process is erring as it cannot calculate the taxes.

Any help would be appreciated.

Thanks,

Jennifer