Until the issue is fixed, you can add a simple script that will remove the height attribute that causes the problem. Here are two examples:

With a RadWindow's ContentTemplate

            <asp:Button ID="Button1" Text="open wnd" OnClientClick="openWnd(); return false;" runat="server" />
            <telerik:RadWindow runat="server" ID="resultsWindow" Modal="true" Height="700px" Width="1100px" VisibleStatusbar="false" OnClientShow="repaintWizard">
                <ContentTemplate>
                    <telerik:RadWizard runat="server" ID="ResultsWizard" ActiveStepIndex="0" RenderedSteps="Active" DisplayProgressBar="false">
                        <WizardSteps>
                            <telerik:RadWizardStep runat="server" ID="SelectStatus" StepType="Start" TabIndex="0">
                                <telerik:RadButton runat="server" ID="StatusWizard" ToggleType="Radio">
                                    <ToggleStates>
                                        <telerik:RadButtonToggleState Text="Passed" />
                                        <telerik:RadButtonToggleState Text="Failed" />
                                    </ToggleStates>
                                </telerik:RadButton>
                            </telerik:RadWizardStep>
                        </WizardSteps>
                    </telerik:RadWizard>
                </ContentTemplate>
            </telerik:RadWindow>
            <script>
                function repaintWizard(sender, args) {
                    $telerik.$(".rwzContent", sender.get_contentElement()).height("");
                }

                function openWnd() {
                    $find("<%=resultsWindow.ClientID%>").show();
                }
            </script>

In a simple hidden div:

			<script>
				function showDiv() {
					var theDiv = $get("testDiv");
					theDiv.style.display = "";
					$telerik.$(".rwzContent", theDiv).height("");
				}

			</script>
			<asp:Button ID="Button1" Text="show div" OnClientClick="showDiv(); return false;" runat="server" />
			<div id="testDiv" style="display:none;">
				<telerik:RadWizard runat="server" ID="RadWizard1" ActiveStepIndex="0" RenderedSteps="Active" DisplayProgressBar="false">
					<WizardSteps>
						<telerik:RadWizardStep runat="server" ID="RadWizardStep1" StepType="Start" TabIndex="0">
							<telerik:RadButton runat="server" ID="RadButton1" ToggleType="Radio">
								<ToggleStates>
									<telerik:RadButtonToggleState Text="Passed" />
									<telerik:RadButtonToggleState Text="Failed" />
								</ToggleStates>
							</telerik:RadButton>
						</telerik:RadWizardStep>
					</WizardSteps>
				</telerik:RadWizard>