This is the fix for toggle button of grid in jQueryUI dialog in IE.
//event callback ( add it in options of pqgrid )
toggle: function(evt, ui){
if(ui.state == 'max'){
$(".ui-dialog,.ui-widget-overlay").css('position', 'static');
}
else{
$(".ui-dialog,.ui-widget-overlay").css('position', 'absolute');
}
}