The tabs get hidden when a top oriented SlidingPane is docked inside a horizontal SlidingZone. The issue is reproducible when the resize mode of the parent Splitter is != AdjacentPane.

Steps to reproduce:
1. Run the following code:

        <div style="padding: 200px">
            <telerik:RadSplitter runat="server" ID="RadSplitter2" Orientation="Horizontal" ResizeMode="Proportional">
                <telerik:RadPane runat="Server" ID="radpane11" Height="20px" MaxWidth="980" Scrolling="None" BackColor="Green">
                    <telerik:RadSlidingZone ID="ListMetricsSlidingZone" runat="server" Height="25px" DockedPaneId="ListMetricsPane" SlideDirection="Top">
                        <telerik:RadSlidingPane ID="ListMetricsPane" Title="DEF" runat="server">
                            1111
                        </telerik:RadSlidingPane>
                        <telerik:RadSlidingPane ID="ListHistorySlidingPane1" Title="XYZ" Font-Size="X-Large" runat="server">
                            222
                        </telerik:RadSlidingPane>
                    </telerik:RadSlidingZone>
                </telerik:RadPane>
                <telerik:RadPane runat="Server" ID="radpane33" Scrolling="None">
                </telerik:RadPane>
            </telerik:RadSplitter>
        </div>

2. Undock and dock a sliding pane.

Expected: The tabs remains visible all the time (change the Splitters ResizeMode="AdjacentPane" for reference)

When a Splitter contains both RadPanes with size in percent and free-sized panes, the width of the fomer is calculated properly only after the initial loading and remains the same the the page is resized.

Steps to reproduce:
1.     <telerik:RadSplitter ID="RadSplitter1" runat="server" Width="100%">
            <telerik:RadPane ID="RadPane1" runat="server" Width="10%"></telerik:RadPane>
            <telerik:RadSplitBar ID="RadSplitbar1" runat="server" ></telerik:RadSplitBar>
            <telerik:RadPane ID="RadPane2" runat="server"></telerik:RadPane>
         </telerik:RadSplitter>

2. Resize the browser.

Result: the size of RadPane1 is not recalculated

Temporary workaround:
Set size in perncent to all RadPanes in the Splitter.

The height of a  free-sized RadPane is not calculated properly on layout mode change in Android devices. The issue is reproducible in Firefox for Android.

Add ability to add border decoration to a RadPane/RadSplitter, without breaking the size of the control.

Add ability to add margin/padding to a Radpane, without breaking the size of the control.