I have a report project which I am trying to pass a dataset with two data tables. This is not really a master detail report, but more of a document that will be saved and printed by the application. I have tried everyway I've seen on the forum to populate the sub report, but nothing works? I've tried setting the data source of the Report property of my sub report, adding code to the NeedDataSource method of the sub report, adding code to NeedDataSource of the actual report that is the sub report, etc. When I step the code, I can see that the datasource is correct when the report is created and the data set has the data, but when the report is generated in the report veiwer, its like it loses the connection with the data. The only time something will display in the subreport is when I hard code values. The only way to get the actual data to display is to make it a separate report. Since I can't get the sub report concept to work, I've decided to just try to use the Report book approach since I have one report for the header, and one for the lines. Is there any problem with using this appoach for my situation? And do you have any ideas why setting the data source for the sub report is not working? I'm using Q1 2009.