Hi Alejandro,
By default, the GridGroupingControl does not support rows with individualized rowheights. To get this support, you need to add a custom GridEngine as in this sample.
Essential Studio\4.2\Windows\Grid.Windows\Samples\Grouping\ResizableRows
If you want the cell to grow as the user types, then you can set the style.AutoSize property to true and the style.WrapText to true. Also set the AllowTextBoxAutoSize property to true.
If you want to auto size it when the cell is not editable or user not typing, then you can explicitly call the ResizeToFit() method.
this.gridGroupingControl1.TableModel.RowHeights.ResizeToFit( GridRangeInfo.Row(4) ); // resizes row 4
this.gridGroupingControl1.TableModel.RowHeights.ResizeToFit( GridRangeInfo.Table() ); // resizes whole table
Here is a sample
http://www.syncfusion.com/Support/user/uploads/GGC_Autosize_44ccd4d7.zipRegards,
Rajagopal