Hello Victoria F,
Thank you for getting back to me.
I confirm that it is possible to have issues with formatting in export hierarchy scenarios, because MS Excel do not natively support hierarchical data and child rows data can get into columns with different type of data.
You can work-around this limitation by manually specifying the value in ExcelCellFormatting event. For example, you can consider the following code:
sender, ExcelCellFormattingEventArgs e)
&& e.GridColumnIndex == 1)
e.ExcelCellElement.Data.DataType = DataType.String;
"my formated value"
Do not hesitate to contact me again if you have any other questions.
the Telerik team
Q2’11 SP1 of RadControls for WinForms is available for download (see what's new); also available is the Q3'11 Roadmap for Telerik Windows Forms controls.