It depends on somewhat on how the report is connectiing to the data. If you use an ODBC or OLEDB connection you will need to make sure it is pointed to the correct db. If you have some other method you will need to make sure it is correct. Often in changing a report I forget to set the report data source location inside of CR so the report is looking at the correct data connection and source.  It could easily be the case the situation here. If you have not done it before, there are several ways to do this so I will let you look at the help file and choose the best method for you.