The viewstate is invalid for this page and might be corrupted

Hi guys. I have following problem and my brains is kind of empty after researching for the fix. I have a asp:Gridview with an Image in the first row. when die image is clicked, a javascript listener reacts to that, opens another aspx-file which just contains another gridview. in the pageload of that grid i manipulate the response, fill the second grid, render the grid and write it in the response. then i end the response. now the grid gets displayed as a subgrid of the grid on the first aspx file. now the user may click any button on the page, that creates a postback. firefox is fine with that. chrome and ie are not. i always get the error message "The viewstate is invalid for this page and might be corrupted". i tried everything i could. viewstatemode = "disabled" for the hole page, for the grids, for the asp-controls ... enableviewstate = "false" for the hole page, for the grids, for the asp controls. activating and deactivating page attributes l ...