From the screenshot, capture.png, I assume that:

• Grid style is customized (not using default style of WebGrid).
• Multi-line text is assigned as the Caption of WebGrid's RootTable.

Set the Height property of HeaderStyle to a bigger size should help resolve the layout problem.

<ISWebGrid:WebGrid ID="WebGrid1" runat="server" ...>
    <RootTable DataKeyField="CustomerID" DataMember="Customers" TableHeaderVisible="true">
        <Columns>
            ...
        </Columns>
    </RootTable>
    <LayoutSettings AllowFilter="Yes" AllowDefaultStyleMerging="true">
        <HeaderStyle Height="60px" />
    </LayoutSettings>
</ISWebGrid:WebGrid>

Please let me know whether this helps or not.