DataGrid: "... is not a valid value..."

I have a datagrid on my form. This is not the original datagrid but is inherited to allow moving columns. The datagrid is bounded to a datasource. It consists of two columns. First it seems like everything works fine. But sometimes I get the error message '200' is not a valid value vor 'value'. 'Value' should be between 'minimum' and 'maximum'. after clicking in the second column. At least I already found out that the number given in the message (in my example 200) is the width of the first column.

Has anybody ever seen such an error message or has an idea what may be wrong?