DataGrid: Let Data Grid know that first line has column names

[runrev260805 at m-r-d.de]

Hi, 

i am fiddling with DataGrids at the moment.  For that i am reading the Revolution_Data_Grid.pdf  and trying out the samples. But i get the sample of page 19 not working

on mouseUp
## Create tab delimited data.
## Note that first line has name of columns.
## Providing names tells Data Grid how to map
## data to appropriate columns.
put "state" & tab & "code" & cr & "ALABAMA" & tab & "AL" & cr & "ALASKA" & tab & "AK" into theText
## Let Data Grid know that first line has column names
put true into firstLineContainsColumnNames
set the dgText [ firstLineContainsColumnNames ] of group "DataGrid 1" to theText
end mouseUp

Nothing is put into the DataGrid.
If i change the line     
put true into firstLineContainsColumnNames
into         
put false into firstLineContainsColumnNames
then the Datagrid is filled. Am i doing something wrong?
Is there a typo in the line? I copied the script directly from the PDF.

Regards,

Matthias