If a Canadian edition of QuickBooks 2006 is the only copy of QuickBooks installed on a machine, then applications built using the QuickBooks SDK, such as Maitre'D 2005, cannot connect to it when QuickBooks is first installed.
Intuit Canada has released a fix to this problem. If the Update QuickBooks option in QuickBooks is configured for Automatic Update then the problem will be corrected automatically.
Otherwise, a QuickBooks 2006 user can correct the problem by following these instructions.