Custom theme in local and online version

[kwitee]

Hi, on my Sliverlight app I am using custom telerik theme: 

// theme declaration
[ThemeLocation(ThemeLocation.BuiltIn)]
public class MyTheme : Theme
{
  public MyTheme()
  {
    base.Source = new Uri("Uri", UriKind.RelativeOrAbsolute);
  }
}

// load theme
Telerik.Windows.Controls.StyleManager.ApplicationTheme = new MyTheme();

On the local computer and LAN it works fine. The problem is when the application is viewed online. The theme is not loaded right away and sometimes it needs a couple of refreshes to kick in. 
How can I solve this? 

Regards, 
-- kwitee