User receives an error while installing BillQuick in which a ReportSourceBridge.dll that Crystal Reports uses fails to register properly. The user has a previous installation of Crystal Reports Runtime.
A similar error occurs in BillQuick Web Suite.
The user has Crystal Reports 2008 Runtime SP1 installed on the system due to which the error occurs. 
When you are installing BillQuick (or Web Suite) and get prompted with the above error message, click Ignore. Finish the installation. Whendone, you will be able to run the reports.
