Hi steve,
What's the version of RadControls you are using? We fixed similar problem a couple of months ago, so if the problem persists with the latest internal build (
http://www.telerik.com/account/downloads/internal-builds.aspx) I would like to as you to open a new support ticket and send us a simple application that could be used to observe the problem, along with the Telerik assemblies.
Using the following XAML and the latest available assemblies, I was unable to reproduce the problem:
<UserControl x:Class="SilverlightApplication1.MainPage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:telerikInput="clr-namespace:Telerik.Windows.Controls;assembly=Telerik.Windows.Controls.Input">
<StackPanel x:Name="LayoutRoot">
<TextBox />
<TextBox />
<telerikInput:RadNumericUpDown TabIndex="1" />
<telerikInput:RadDatePicker TabIndex="2" />
<TextBox TabIndex="0" />
</StackPanel>
</UserControl>
Greetings,
Valeri Hristov
the Telerik team