Change QuickBooks Filename
You should not reinstall the web connector. Whenever you send it to your accountant or expect a filename change for any other reason, you should disable the sync by opening the web connector and unchecking the autorun check box. Otherwise, we could be updating your old file.
To get it working for your new file, you'll need to go to Settings->QuickBooks. Scroll down to Enable QuickBooks Desktop Integration and click the show/hide link. Update the file name and click Save Location. Make sure you leave the .QBW extension. It is required.