DataGrid header style has problem in IE8

[tong123123]

as shown in the attachment, in IE8, in datagrid header, even I set the <thead> element background color to #bcee68, the result is just separate <th> in the <thead> is change background color, not the whole <thead>
I found this problem only occur in IE8, but not in firefox.
also, this problem will not occur when first load the page or the datagrid's row has contents, the problem only shown when the search button is pressed and no result return.

How to solve it?

I try to set the background color of <table> element inside datagrid, but this will cause the background color of the  label "record not found" changed also.

[Thomas Broyer]

You'll have to apply the style not only to the thead but also the th it contains.

[tong123123]

the problem still exist even I use
.classA THEAD
.classA THEAD TH
in my css.

when the user interface is first load, the whole header background is changed, but when pressed search more than  once and no result return, then only the <th> element background is changed as attached.
this problem only occur in IE8.

[vijay gohel]

Please apply column width of datagrid.setColumnWidth method it will set header fix and white space will not display.

Example  datagrid.setColumnWidth(projectCode, columWidth + "px");