I am creating an installer for my program using WiX (Windows Installer XML). I have used the following code to begin using the built-in WixUI Dialog Sets:

<Product ...>
  <UIRef Id="WixUI_FeatureTree" />
</Product>

This, however, creates a dialog set with horizontal lines that are just a little bit too short on every dialog as shown here:

I understand that I could create my own set of dialogs to use instead by using software such as SharpSetup and WixEdit but I like the dialogs that WiX creates and only want to make a very small change to them.

Is my best option to download the WiX source code and try to modify it? Is there a more simple solution? Perhaps I should contact the developers of WiX to list it as a bug? Maybe they like it that way though. I however think it looks out of place and would like to change it.

I am using the latest weekly release of WiX 3.5.