Hi
Thanks for your reply

Strange, the result is the same with setting focus.
I wonder if is something about video drivers.

>Dorin,
>
>I don't believe this is a VFP bug per se. In your sample form I only see one brief flicker when clicking into the frontmost grid to give it focus so that it heeds the mousewheel rolls. Before clicking the grid no amount of mousewheeling over grid2 or over the space occupied by grid1 causes any flicker or grid scrolling for me.
>
>I believe that the issue here is your "non-visible" grid has focus and it's behind the other grid. If you add this line I see no flicker of the undergrid at all:
>
>

>   PROCEDURE Init
>      this.grid1.RecordSource = "test1"
>      this.grid1.Refresh
>      this.grid2.RecordSource = "test2"
>      this.grid2.Refresh
>      this.grid2.Setfocus() && put focus onto the visible grid
>

>