[TOBAGO] Stick items at the top

[AM]

Hello dear users!

(in this case an item is my tc:box)
I have a layout-problem only when i use Firefox. My tc:box shown below is
centered at the height of my display, but with IE it works well and is also
always sticking near my menue-bar at the top.

at the faq i found this link:
http://myfaces.apache.org/tobago/compatibility.html
and i also tried to run my appl. with ff9 :(

I use: tobago v 1.0.38
and myfaces 1.1.8

My code (prblem):
<layout:proj>
    <jsp:body>
        <f:facet name="layout">
            <tc:gridLayout rows="fixed;*"/>
        </f:facet>
        <tc:box label="Login">
            <f:facet name="layout">
                <tc:gridLayout rows="fixed"/>
            </f:facet>
            <tc:panel>....</tc:panel>
        </tc:box>
        <tc:out/>
    </jsp:body>
</layout:proj>

My code menubar (if necessary):
<f:facet name="menuBar">
    <tc:menuBar>
    <tc:menu> ...... </tc:menu>
    </tc:menuBar>
</f:facet>


thanks a lot and wishing a restful weekend! :)