1. Incorrect Structure of Columns or DetailTables. 2. Misusing or Not Using NeedDataSource Event 3. Using EnableViewState = false in Non-supported Scenarios 4. Using Cell Numeric Index to Find a Cell in a GridItem Instead of Using Item's String Index by Column.UniqueName 5. Finding Controls Inside RadGrid

1: Binding the datagrid to a datareader instead of dataset, because the datareader is connected, i.e. you have to keep the connection open while the grid is there, while the dataset is disconnected, you can close the connection as soon as you have the data.

2: if you have huge number of records, don't use the normal paging technique, because even if you make the paging for every 50 records, each time you request the bind of the grid, it brings all the data from the server, so you have to use custom-paging in order to bring only current data.