Following way can fix this issue for Bootstrap v2.3.2, Kendo UI Grid version 2013.3.1119.340 in IE11.
the point is remove class "in" from modal's class. No need to use "style='display:none;'" since it will cause Kendo Grid UI oddly.
html codes before fixed:
html codes after fixed:
same time, add following line of javascript:
$("#YourWindow").on('shown', function () {
$(document).off('focusin.modal');
});