What Event/Method of what control this code is in? How and when it gets called?

>The following code in a grid crashes with message "data type mismatch" on a client's computer but not on mine here. I experimented with .rowsource = "" (it was crashing on NULL) but same error message.
>
>At the time the grid's recordsourcetype = 1 - alias and recordsource is (none)
>
>how can this be?
>
>
>

>LPARAMETERS vNewVal
>
>* 11/02/2009 PHIL SALES MATRIX - Allow an order or a quote to be raise - Obscure bug when nudging use nudgec class
>* When this sets DATASESSION this gets called and it then says cannot access (This.Parent.cursornameforentries)
>
>IF NOT TYPE("vNewVal") = "C" OR vNewVal # This.Parent.cursornameforentries
>* TPMcD	27/02/09	This.Column2.Ascombobox1.RowSource = NULL
>	This.Column2.Ascombobox1.RowSource = ""
>ENDIF
>DODEFAULT(vNewVal)
>