Repeat table group on print pages

[matteo]

Hello, I'm working on a printing solution based on asp.net Rad GridView control. The print page is a long radgrid with headers and one grouping level. I need to show the columns header on all the printed pages, and I've successfully used the CSS rule :

thead
{
    display:table-header-group;
}

tbody
{
    display:table-row-group;
}

Now I need to show on each page the group header, I saw that the group header is rendered with this HTML:

<tr class="rgGroupHeader">
        <td class="rgGroupCol"><input type="submit" name="ctlrReportDesigner1$RadGrid1$ctl00$ctl04$ctl00" value=" " title="Collapse group" class="rgCollapse"></td><td colspan="3"><p>My Group Header</p></td>
    </tr>

I've tried to apply to the rgGroupHeader the table-header-group but with no luck, the style seems to be applied only to thead elements. The question is: how can I show the group headers on all the printed pages? Can I change the format of the table group and transform it in N sub-tables with thead and tbody?